Thursday, November 24, 2011


As proof of non-slackage, I offer the following in-class activity developed for my intro astro for non-scientists class.  Students work out the length of the solar days on Mercury and Venus using those planets' orbital periods and sidereal days.  Usage in classes, comments, and suggestions are all welcome.

Wednesday, November 9, 2011


Research time has been scattered lately, what with funding proposals and other demands.  Only thing to report is that collaborator Jianfeng Wu's look at the newly public COS spectrum of PHL 1811 revealed that it did not turn into a BAL quasar, which would have been a simple solution to the mystery of its weirdness.  Nature isn't so simple, it seems.

A paper to referee and then I'm back to my own research in more than just interstitial time.

Wednesday, October 26, 2011

"Jimmy Carter's passed out on the couch."

Yep, it's the season of applying for financial support for my research group.  Nat'l Sci & Eng Research Council, MITACS for a visiting summer undergraduate, France/Canada Research Fund.

Also working on AGN science working group interim report in support of the next generation CFHT idea.

So, very busy.  Though deadlines are helping push some papers towards submission!  And attending a conference on my research area right around this time has fueled lots of good ideas which will hopefully garner some support for both me and the ngCFHT.

Friday, October 21, 2011


Last Saturday through Tuesday I was at the "AGN Winds in Charleston" (South Carolina) conference.  A very good conference.  Lots of ideas to implement in papers and my grant proposal (I missed out on a $100 research funds top-up  by turning in the latter to York for internal review today instead of Tuesday).  Said ideas will pop up on this blog from time to time, I'm sure.

Saturday, October 15, 2011


Concluded a useful reading week visit to Penn State yesterday, working with Niel Brandt, his students Nur Filiz Ak and Jianfeng Wu, and briefly chatting with my future postdoc Paola Rodriguez Hidalgo.  Talked mostly about broad absorption line quasar variability, which is a complicated phenomenon in which simulations lag observations.  Resolved to ask theorists what measurements would be useful for them to have, as theorists and observers are now mingling at the AGN Winds in Charleston meeting (of which more anon).

Tuesday, October 4, 2011


Have been preparing for the traditional post-sabbatical colloquium in our department which I gave today, on BAL quasars with redshifted troughs.  Very useful to spend the time making figures in SM and thinking about the various possible explanations for these weirdos.

Also realized I can see Canada's Wonderland from my office window.  How did I not notice that for seven years?

Friday, September 30, 2011

Blinking Cursor

Research-wise, this week was Rogerson research evaluation, and some discussion of the BAL photovariability project.  DeRobertis pointed out in the evaluation that if an absorbing cloud at a fixed distance from a quasar expands and decreases in density, it can effectively photoevaporate in an ion of interest (n goes down, L and d are constant, so ionization parameter U=L/nd^2 goes up).  I don't think anyone's considered that possibility for BAL variability before.

Sunday, September 25, 2011


Chajet research evaluation passed; we resolve to make some better figures.
Read over redshifted BAL troughs ESO proposal.
Read over drafts of Rogerson research evaluation.
A few revisions to redshifted BAL draft paper.
That plus teaching, the parents in town, and being a bit under the weather fills up the week.

Tuesday, September 13, 2011


Passed the 100-post mark without noticing.  Guess I'm getting forgetful.

Mon.: Continued reading paper for journal club.  Skimmed another paper for colleagues.  Brief discussion with Chajet.  Email responses to Filiz Ak.  Incorporated textual revisions to redshifted BAL quasar draft.  ngCFHT.
Teaching: lecture prep, wrote & sent TA email.  Moodling.

Tue.: Inclination-angle revision and email. Journal club. ngCFHT. Teaching: Moodling, Bit of TA organization.

Friday, September 9, 2011

The Secret of Comedy

Bus ride to York: finished reading parts of consultants' report on CDN astronomy. Mildly edifying.
8-10:15 am: E-mail; course preparation online.
10:15-11:45 am: Teaching.  Sabbatical indisputably over now.
11:45-12:30: reading draft research evaluation for Chajet; e-mail.
12:30-1:15: Journal club.
1:15-2:30: e-mail, discussion of draft research evaluation with Chajet.
2:30-6:30: thinking about polar broad absorption line quasars, keeping up with email/newsletters/etc.

9:30-10:30: outlined calculation of unobscured line-of-sight distribution in Lawrence & Elvis tilted-disk obscuration model and a variant thereof.
10:30-11:30: ngCFHT.
Bus ride to York: reading preprint on AGN-driven galactic winds.
12:30-1:30: Physics grad student orientation BBQ.
1:30-2:15: emailing students in intro astro class.
2:15-9:00: ngCFHT, mostly.
9:00-9:30: tweaks to tomorrow's class slides.

8:00-8:30: email, quick response on redshifted BAL quasar draft.
8:30-10:15: teaching work in Moodle, mostly.
10:15-11:45: teaching
11:45-12:15: lunch
12:15-1:00 teaching work
1:00-2:15: randomly inclined disks writeup & extension.
2:15-7:15: ngCFHT and student emails; some discussion of L&E unobscured sightlines.

Tuesday, September 6, 2011


Breaking things down more than usual this entry, for my own edification:
Bus ride to York: wrote paragraph on ideas for followup work on redshifted BAL quasars
8-9 am: updated solar system model @ York website, thought & wrote about spectropolarimetry of above
9-10 am: thought & wrote about redshifted BAL quasar variability &c.
10-11 am: wrapped up internal draft on redshifted BAL quasars.  Whew!
11-12 am: lunch, errands, short summary of paper on CIV/MgII emission on shareflow
noon - 1:30 pm: website prep for teaching tomorrow, errands
1:30 - 2:30 pm: prepped digital cameras for checkout by students taking constellation photos
2:30 - 3:30 pm: finished website prep for teaching tomorrow, brief chat with Rogerson re: research this month.
Bus ride home (early to avoid the rush): reading a little of a consulting group's report on Canadian astronomy
Evening: project management style discussion & implementation of a few more teaching items.

Thursday, September 1, 2011


Skimmed paper on emission from narrow-line Seyfert 1 galaxy 1H 0707-495 right down at the event horizon.

Looked at some new figures from Chajet, and discussed results.

Redshifted-trough BAL quasars: looked at images for signs of binarity; made lots of spiffy figures; revised most sections of the text (but two figures and two sections remain).

Resolved an issue regarding average inclinations of randomly inclined disks: the median inclination angle (i=0 being face-on) is 60 degrees, but the mean is 57.3 degrees; and are thus in agreement.

Wednesday, August 31, 2011


Redshifted-trough BAL quasars (not tired of them yet!): trimming the fat from the draft paper.
E-mail regarding possible cases of BAL trough acceleration.
Evaluating cases of possible Fe III UV50 BAL absorption (only 1 or 2 survive).

Monday, August 29, 2011

And so to bed.

Final tweaking, then submission of postdoc funding application.

Setup Anti-repetitive strain injury app from on my laptop, as well as K9 website blocker ...had to unset all their defaults, since this isn't to block unsavory content, but rather to block the handful of websites to which my attention wanders a few too many times during the day (slashdot, Krugman's blog, a few others).

Tracked down SDSS DR7 IDs for a few dozen quasars with Stripe 82 light curves.  A few are quasars missed in the DR7 catalog.

Also read a bit of radio astronomy background while waiting to get a haircut.

Friday, August 26, 2011

Goes Here

Perusal of archives.
Emails about weak-lined quasars.  (Thought of potentially neat way to apply K-S test to datasets with upper limits.  Forking my consciousness to pocket universe to investigate further.  (If only.))
Revision of postdoc funding application.
More fun with redshifted BAL quasars.

Thursday, August 25, 2011


Spent the day (and it ain't over yet) commenting on various research projects other people are leading.

Wednesday, August 24, 2011

This Is The Week That Is

Monday, wrapped up initial preparations for teaching starting next month and chatted with Chajet about next steps for the MHD wind modeling paper draft.

Yesterday and today, working on redshifted-absorption BAL quasars.

Yesterday was also going-away lunch for Rafiee.

Also signing a few forms every day in my capacity as acting chair of the department.  I am mad with the power.

Monday, August 22, 2011

That Was The Week That Was

Let's see if blogging can be more regular this coming week.  Last week included:

Undergraduate teaching prep: decided not to use clickers this year (but
will still do in-class activities); helps to keep costs down for students.
Revised fall term project and most lab activities.

Science: read over paper draft by Chajet.
Matched some BAL catalog files for Rogerson.
Plotted up and thought about all new redshifted-absorption BAL quasar candidates.

Friday, August 12, 2011

Good work, but where did the time go?

Looked at some candidate BAL quasars with redshifted absorption, which included writing some new SM code.
Sent some emails regarding near future plans.  Wrote abstract for upcoming conference, and collaborated on students' abstracts.

Thursday, August 11, 2011


Yesterday was journal club on the preprint in yesterday's post, plus selecting papers for future quasar clubs, plus some thinking about teaching this next year.

Today was financial matters; commenting on a BAL variability draft; commenting on a weak-line quasar draft; putting a quick paper summary on, and sorting some papers in my office.

Wednesday, August 10, 2011


Dr. Faucher-Giguere,

I read with interest your preprint on FeLoBALs.
Very nice work.

I do have some comments and questions about which I'd be interested in
hearing your thoughts.  The length of the email just reflects the strength
of my interest.  I've also posted this email at
if you want to discuss it in that forum (I won't post private replies there).

First, I think it's misleading to use the term "quasar blast wave".
It had me thinking you were NOT modelling the case of a steady
quasar wind inflating a bubble, until I got to the appendix.
Wouldn't replacing "blast wave" with "shock wave" or
"quasar-driven shock wave" be more appropriate?

Second, to make the paper more accessible to observers, I think it's
important to introduce the Figure in the Appendix right at the start of
Section 2.  The oversimplified picture observers have (myself included) is
that a quasar wind is in a free expansion phase, driving a shock outwards
at v_sh ~ v_in, with negligible swept up mass.  But as you point out, the
properties of the swept-up gas and not the initial wind govern interactions
with the ambient medium.  So Figure A1 needs to be emphasized in the main
text as _the_ picture to keep in mind.  E.g., without the appendix figure
it's was hard for me to picture how v behind the shock could be < v_sh.

I would also suggest using the term "wind shock" (McKee & Hollenbach 1987,
Fig. 4) instead of "reverse shock".  The latter implies to an observer like
me a shock which is propagating backwards, but that's not the case here
(though not impossible I suppose).

A related comment is that I went looking at the Koo & McKee paper, and
references therein, for a simple outline of why the wind forms a structure
like that of the appendix figure.  Such an outline would be useful to add.
Something as simple as: the wind first freely expands and shocks the ambient
medium; that ambient shock and the leading edge of the wind slow down as
material is swept up; the leading edge of the wind is shocked by the wind
behind it, forming the wind shock interior to the ambient shock.
[Koo & McKee mislead readers at the start of their section 2 by incorrectly
claiming that the velocity of the ambient shock is > than the initial wind
velocity.  It took the above McKee & Hollenbach reference (and Koo & McKee
Figure 4) to clear that up for me.  And it's a point worth making, I think,
that even if the observed FeLoBAL gas is fully accelerated to v=v_hot, that
velocity is less than v_in of the driving wind.  And if I got anything wrong
in my comments above, that just proves my point for adding an outline...]

Also, in the Appendix: clarify that the contact discontinuity separates the
shocked wind and shocked ambient medium, which are assumed to be immiscible.

Third, you conclude the appendix by saying that Mdot_in and v_in can't be
separately inferred; that seems true if all you know is R_s and properties
of the gas near R_s.  But is it impossible in principle, if you knew all
other parameters of the outflow?  Mightn't different (Mdot_in,v_in)
combinations at the same Edot produce different R_sw, for example?
Or could you maybe use momentum arguments to estimate Mdot*v_in and
combine that with Edot_k to get Mdot and v_in?

Fourth, regarding the first sentence of the discussion:
even if FeLoBAL absorption systems are distinct from Hi/LoBAL systems,
FeLoBAL quasars themselves might not be distinct from Hi/LoBAL quasars,
in the sense that FeLoBALs will only be seen along sightlines where quasar
winds (i.e. Hi/LoBALs) exist.  There are of course some workarounds
which could cause FeLoBALs to be seen in objects without Hi/LoBALs:
* if a wind exists but is all so highly ionized it doesn't show CIV,NV,etc.
* if a Hi/LoBAL wind doesn't currently exist, but used to.
* if your idea of Omega=1 for FeLoBALs at kpc scales is correct.

A way to constrain some of the above is to compare the relative numbers of
FeLoBALs with all transitions (Fe II thru C IV) covering the same velocity
ranges, i.e. consistent with absorption only from swept-up clouds, and of
FeLoBALs with HiBAL absorption at a much wider range of velocities.
The former would be non-BALs if you took the FeLoBAL gas away;
the latter would still be BALs.  If your idea of Omega=1 for FeLoBALs is
correct, there should be from 1.5 to 3 times as many of the former as of
the latter (for 40% and 25% BAL fractions, respectively).

Looking at the objects in the paper in terms of the above:
J0838 is a case of the latter; component c is an FeLoBAL system,
but there are other components a and b which are HiBALs.
J0318 is a case of the former.
Q2359 is in between; it has higher-velocity systems only seen in MgII
(it's too low z for C IV coverage from the ground)
but the strongest system is the one with FeII.

Regarding the Omega=1 suggestion, is there a way to estimate the timescale
over which the hot gas will expand laterally, and compare that to the flow
timescale?  Of course a pressure gradient will drive lateral expansion, but
the timescale would have to be comparable to the flow timescale for the
gas bubble to end up with Omega=1 by the time the FeLoBAL region is reached.

Fifth, in section 2.2 it seems to me that one further step would be useful:
giving the pre-existing density above which post-shock gas _would_ cool in
a flow time, and then showing that such densities are almost never plausible.
If I've done the math correctly, post-shock gas will cool in a flow time if
$\bar{n}_H^{pre} > 330 yrs T_{sh,9}^{1/2} (v/10,000 km/s) (R/3 kpc)^{-1}$.

Lastly, a minor point, but I would suggest replacing "QSO" with "quasar"
or "Q" (for variables) throughout, at least if you share my preference for
a made-up word over an acronym...


Tuesday, August 9, 2011


Trying to catch up and then resume regular blogging, so this post covers everything since the last one.  Everything that comes to mind, anyway:

* caught up on Jesse's blog, and discussed BAL quasar photovariability ideas
* brief discussion of disk wind modelling with Laura
* read referee's report on paired sightline MgII absorption and discussed revisions & response with Jesse
* read over referee's report on polar BAL paper and have begun revising & responding
* submitted notice of intent to apply for a Discovery Grant (Canadian govt funding for scientists and engineers), which involved a fair bit of background thought & planning for how to approach the actual proposal
* read Stu Dack's thesis
* revised syllabus for winter term class on radiative transfer
* started reading preprint on FeLoBALs
* started planning for full-year NATS astronomy course I'll be teaching

Wednesday, July 27, 2011


Back in Toronto, back at work (though not always research work).

Monday I revised the syllabus for the radiative transfer course I'll be teaching next winter term, and replied to emails regarding (amongst other things): my yearlong astronomy-for-non-scientists course, published BAL catalogs, and a newly-stumbled-across FeLoBAL quasar.

Tuesday I ordered a new computer for research and teaching, and caught up on more email.

Sunday, June 26, 2011

Two papers relevant to MgII absorption around galaxies

Will need to reference both these papers in passing in our revised paper testing the Tinker & Chen MgII halo model.

arXiv:1106.0616 Bordoloi et al. The radial and azimuthal profiles of Mg II absorption around 0.5 < z < 0.9 zCOSMOS galaxies of different colors masses and environments

They can't say anything about covering fraction using composites, but can constrain strength of absorption with radius.  Need to mention how consistent their results are with Tinker & Chen's.

Fig. 3: absorption quite weak in composites.  Some smearing will have occurred, due to velocity offsets. 

Fig. 5a: abs. detected out to 100 proper kpc at EW~ few 0.01 Ang for non-group galaxies, but need to check what EW threshold Tinker & Chen had; if TC had a threshold of EW=0.1 Ang, they would have detected absorption only out to ~70 kpc.

We should point out that quasar asterisms offer the chance to probe the variation in absorbing EW with azimuth in individual halos, whereas this work's approach can only study statistical azimuthal variations, and then only for inclined disk galaxies.

arXiv:1106.1642 Lundgren et al. The Dark Matter Haloes and Host Galaxies of MgII Absorbers at z~1

Abstract:  They find from a sample of galaxies at 0.7<z<1.45 that the halo mass of MgII absorbers is the same as at z~0.6, which is good news for us because we don't model any redshift evolution in the halo mass distribution of absorbers.  Their f_c=0.5 (based on 1 detection! see section 6) is consistent with our measurement of f_c. 

Note that they have a sample of only 21 strong MgII absorption systems detected in SDSS quasars with which to compare to a large galaxy sample, and they only usefully probe scales of >~1 h^-1 Mpc from those absorbers with those galaxies.  (They detect MgII absorption in 2 of 3 cases of separations < 60 h^-1 kpc.)

Note that their Fig. 5 shows a slight preference for radius evolution of absorbers, despite being consistent with no evolution.  But what they're cross-correlating with their galaxy sample is a random point in an MgII halo (random because the quasar position is randomly placed within the halo), and that will increase the uncertainties a bit... hopefully they've tried to account for that in their uncertainties.

Friday, June 24, 2011

BAL Lac Objects?

Sent the following to

Dr. Zhang,

I read with interest your recent paper on a variable BAL trough in a
BL Lac object (arXiv:1106.1587, Discovery of A Variable Broad Absorption Line
in the BL Lac object PKS 0138−097).  The object is definitely worth following up
when it's in a high state to see if the trough shows up.  However, I'm not quite
convinced the trough is real.

The 4200 Ang feature seen by Stickel et al. could be explained as just
narrow MgII absorption observed at low resolution.  Whether or not there
is additional (broad) absorption in the S93 spectrum seems to me
critically dependent on where the continuum is drawn.

However, the main reason I'm skeptical is that the strongest trough is seen
in a SDSS observation with fiber 73 (MJD 53729, plate 1914).  There is a
problem in the SDSS #1 blue CCD which may explain this feature as spurious.
Here's my footnote on that problem, from an unrelated paper in preparation:

The SDSS spectrum of the BL Lac object OM~280
(SDSS J115019.21+241753.8; 2510 53877 086)
appears to show a trough at $\sim$4150\,\AA.  This trough is spurious,
likely arising from a region of non-optimal flatfielding (e.g., due to a
localized variable feature in the flatfield) in the CCD in the blue arm of
SDSS spectrograph \#1.  This region is visible as a faint circular depression on
the reduced 2-D spectrograms of that CCD in that wavelength range, centered
near fiber 81.  The affected wavelength region is interpolated over for
fibers 78-84, but its effects can sometimes be seen in other nearby fibers
such as \#86 (used for the spectrum of OM 280) or \#76 (producing a similar
spurious trough in SDSS J115013.88+234602.1). 

If the broad feature in the fiber-73 (MJD 53729) spectrum of your object turns
out to be spurious, then the reality of the feature rests on the MJD 52174
spectrum and the Stickel et al. spectrum.  The features in those spectra might
not be real broad troughs, which is why I'm not convinced.  But I agree they
could be real, which is why I think followup observations are merited for
this object, and I hope you pursue them.

Patrick Hall

PS  Note that a more accurate name for the object is PKS B0138-097;
the IAU asks that the B or J always be included to indicate the epoch,
and PKS 0138-097 recovers the object in SIMBAD but not in NED.

Also, I find it helpful to include not just the MJD of the SDSS spectra
in a publication, but the plate and fiber numbers as well.

PPS  The raw SDSS 2-D spectrograms can be found at
sorted by MJD, with names corresponding to those found in the
EXPID01, EXPID02 etc. header keywords in the spSpec files.

Wednesday, June 22, 2011


Between vacations.  Since Saturday I have gone through astro-ph (though have only looked at one paper in detail) and email (responding to all the easy items) and have Skyped with Chajet, with Rogerson scheduled for tomorrow.  Also on my plate for the next 7 days, in rough priority:

* weak-lined quasar spectroscopy: Gemini Phase II
* stay on top of: NATS1740, new computer, grant proposal letter of intent
* send ngCFHT AGN SWG invites
* Polar BAL quasar paper resubmission
* Redshifted-trough BAL quasars (annoying that the most fun thing is the lowest priority)

Friday, May 20, 2011

On Holiday

Well, not quite yet, but I shan't post again before I head off for 4 weeks' vacation.

Sent thoughts on BAL variability to SDSS-III collaborators and Jesse Rogerson, who has started looking at quasar (& specifically BAL quasar) color variability.

Plugging away on redshifted-trough BAL quasars; can't say much online since it involves SDSS-III data.  Probably worth stepping away from it for a while and getting reinvigorated, as I've reached a point where lots of the easy work has been done (though some remains) and am starting to think of the more complicated and time-consuming things that may need to be done.  Will post as an SDSS-III collaboration project before heading off; with luck collaborators will join and do work while I'm away!

Tuesday, May 17, 2011


Polar BAL paper submitted.  Rogerson & Hall MgII absorption paper submitted.

Final skype w/Chajet before both our vacations.

Work on BAL quasars with troughs at redshifted velocities continues.

Will juggle that with BAL variability work this week.

Friday, May 13, 2011

Who Ordered Them?

BAL Quasars with redshifted troughs, that is.  Been thinking and writing about them.

Also skype with Laura Chajet.

Also commented on latest draft of Jesse Rogerson's Master's Thesis paper.

Also attended 5 out of 8 Lectureship Colloquia held here this week.

Thought a bit about a paper on another polar BAL quasar pointed out by a colleague.

Tuesday, May 10, 2011

Two Dollars

Monday, posted polar BAL quasar manuscript. 

Tuesday, talked with Joe Hennawi for a while and Jon McKinney for a bit.

Thought about BAL quasars after that.

Reviewed Rogerson & Hall manuscript.

Wednesday, May 4, 2011


Hadn't realized I posted so little in April.  Have been working on:

* Improving MATLAB code for disk wind modelling, and running models.  Going OK, but just recently some weird profiles have turned up, so I need to make sure they don't reflect any bug(s).  And some more wind streamline laws need to be coded in, to explore a bit more parameter space.

* Thinking and writing about "polar" BAL quasars.  I random-walked my way to disproving them.  In the long run worth doing; in the short run mildly annoyed at all the dead ends followed.  Everything is more complex and takes longer to understand than you imagine it is and will at first.

* Measuring some spectral parameters for weak-line quasars, as a follow-on to the PHL 1811 analog work.

Today am going to look at some BAL quasar spectra from SDSS-III.

Tuesday, April 26, 2011

Weekend Paper

One thing I wanted to try on my sabbatical was writing a very short paper over a weekend.  Didn't quite make it (and it was even a long weekend!), but I mostly ruled out "polar" BAL quasars; remaining tasks are:

DONE: 1) Check my math, both formulas and numbers.

DONE: 2) Dig up the FIRST and NVSS peak flux densities AND THEIR UNCERTAINTIES for both epochs for all the objects in Table 1.

DONE: 3) Take the formulas for rmax (Eqs 4 & 5) and beta_perp^min (Eq 9), come up with formulas for their uncertainties.

DONE: 4) Compute uncertainties on rmax, T_b,q and beta_perp^min using the errors on fluxes found above.

DONE: 5) Discuss more references, write conclusions.

I'll let it sit a week for Laura and I to look it over again, then submit!

Thursday, April 14, 2011


Am focusing on disk wind line profile paper, so previous post may be updated more often than new posts made.

Last week and a half has been some disk wind thinking, a bit of X-ray thinking, a Gemini referee report, Skype with Rogerson and with Chajet, but mostly a whole heck of a lot of postings about papers from the literature on Shareflow. There's a whole bunch of annotated hardcopy papers I won't be taking back across the pond with me....

Monday, April 4, 2011


Time to start pushing my long-delayed paper on accretion disk (AD) winds out the door.

To Do List (more or less priority ordered)

* MOSTLY DONE (re)read related papers & post on ShareFlow
* MOSTLY DONE reread paper, freshen up text, verify paper structure ok, ID any new "to do" items

when I was last working on the paper intensively, I left several questions hanging; need to decide which to address and which to leave for the future:

* Finally understood; program adjustment DONE: is Q only important in the 0.3 < tau < 3 regime?
* expressions for Mdot = 4 pi rho(r) r^2 v_r(r) C_f(r) = const for r>r_launch,max

* DONE Matlab implementation of conical emitting region equations
* DONE add erfc() to tau, and Q-dependence in denominator of x^2
* share Matlab diagnostic programs
* log-linear Q
* Knigge et al. Q

* what parameter space to study in first paper
* which lines: CIV, MgII, demo CIII? Ha,Hb? (but comparison with RM not possible yet)
* which parameters to vary, and over what ranges?

* for them, do final line profile runs for varying wind launch angle and inclination

* Fine et al. style analysis of sigma(FWHM) distribution (CIV and MgII)
* blueshifts
* EWs

* convert latex to MNRAS style
* write up results of Fine et al. style analysis
* update references


Finished and gave talk on PHL 1811 analogs to IoA X-ray group on Friday, after considerable background reading. Good point from Andy Fabian led me to investigate reflection-dominated X-ray spectra and think about models of AD spectra; will post to Shareflow soon.

Thursday, March 31, 2011

Vive le FPG

Thought about [O III] and Fe II (should post to shareflow soon).

Investigated SDSS-III spectra. Vive le French Participation Group! Their qso value-added catalog saved me days of work.

Submitted WLQ GN proposal.

Prepared talk on WLQs/PHL 1811 analogs for tomorrow.

Tuesday, March 29, 2011


Have been:

* finalizing post-referee resubmission of SEB paper with Rafiee.
* converting WLQ Hbeta-spectra proposal to MgII with Ohad Shemmer et al.
* finalizing post-referee resubmission of PHL 1811 analog paper with Wu, Brandt, Richards, Shemmer, Gibson. Much discussion and figure-tweaking.
* brief email discussions with Chajet and Rogerson.
* reading a few papers to post to ShareFlow soon.

Friday, March 25, 2011


Reading about ICA.
Skype w/Rafiee.
Chat w/Hewett.
Revised PHL 1811 analog / WLQ unification figure. Much discussion ensued.

Thursday, March 24, 2011


Shareflow postings on BAL & BLR X-ray observations.

Tweaking of PHL 1811 draft, per suggestions by Rob Gibson.

Draft PHL 1811 / WLQ unification figure.

Reading up on Mean-Field ICA. [Wrote it in my blog, now I have to do it.]



Skype w/Rogerson, working on revised contour plot of allowed parameter
space regions for Chen & Tinker model.

Finished (I think) incorporating recent conical-emission-region refinements
into MATLAB disk wind code. Email w/Chajet about that and FWHM comparisons.


X-ray posting on shareflow, and leafed through a few other papers not worth
posting about.

Revised NATS1740 mini-calendar text, and consideration of new textbook edition.

Quasar club skype: part 2 of Netzer et al. 2008.

Skype w/Rafiee, discussion of SEB paper.

Shareflow postings on emission-line FWHM correlations with radio properties.

Monday, March 21, 2011


Skype with Laura Chajet: beginning to incorporate recent refinements into code, and to set up framework for comparison of observed dispersion of emission line widths with disk wind model predictions for same.

Reading about Independent Component Analysis.

Comments on PHL 1811 analog draft.

Comments on plots on results of MIPS observations of FeLoBALs.

Predicted X-ray weakness of 6 weak-lined quasars based on optical/UV spectra. Watch this space to learn how well I did....

Thursday, March 17, 2011

Wednesday, Thursday

* e-mail discussion with Chajet finalizing accounting for a conical (not disklike) emission region in our disk wind modelling

* final comments on resubmitted Rafiee & Hall DR3 BH mass catalog paper, and on coding for rerunning DR7 BH masses

* inspection of Plotkin et al 2010ab weak-lined quasars, pulling out a few more redshifts along the way; a fair number of them show properties consistent with unification with PHL 1811 analogs

* thinking about BAL quasar continuum reconstruction

Wednesday, March 16, 2011

Midweek in Review

Spent time over weekend and Monday/Tuesday investigating PCA fits and mass estimates for DR7 quasars. Rafiee is now running PCA fitting with revised error calculation.

Also thought a fair bit about simultaneous reconstruction & dereddening of quasar spectra.

Skypes with Chajet and Rafiee on Monday.

Tuesday: Finished reading, and sending email to, Jon Trump on his recent paper. Also spend more time thinking about PHL 1811 analogs, and inspecting candidate analogs/WLQs from Plotkin et al. 2010ab.

Monday, March 14, 2011

Testing, Testing

Over the weekend I finished some investigations of X-ray objects from the forthcoming paper by Gordon's student. Nice relationship between alpha_ox and CIV blueshift turned up.

Testing some wikidot functionality here:
\beta i \tau\ epsilon = \mu \eta
Didn't think it would work, but worth a try.

Friday, March 11, 2011

Week in Review

Wednesday: Thought of another minor correction for disk wind emission. Helped out with PHL 1811 analog proposal for Chandra.

Thursday/Friday: Read draft DR3+DR7 MBH+PCA catalog paper. Rafiee pointed out a number of extra spectra he had run PCA fitting on. Examination of them revealed 16 good spectra (but no new objects) which I added to master list of SDSS quasar spectra. Skype w/Rafiee; he will refit objects with bad FeII fits with a different starting normalization.

Also spent time looking at SDSS objects w/X-ray data, & potential targets for such. C IV absorption distorts their EW-bshift locations, but doesn't get rid of all objects with weak but unblueshifted CIV. Using Shen et al. 2011 blueshifts (relative to MgII) and EWs doesn't either, although the EWs seem less affected by absorption.

If A Planet Died, Would We Notice?

Would the impact of a planet on its host star yield a noticeable brightening if it happened to occur on the side of the star facing you?

First, can a planet impact its host star? Yes, if it is solid and more than twice as dense as the star. So only the cores, not the gaseous envelopes, of hot Jupiters are likely to impact their host stars (the envelopes will be tidally stripped first). If the planet is molten then some or all if it might be tidally stripped before impact. But as long as the stripped material stays high density it should produce the same luminosity from shocked gas on the star's surface, just more spread out over time, as the tidally stripped material will be spread out before and behind the planet in its orbit.

A way to estimate the impact luminosity is to take a spherical planet of a certain density and radius R_p, give it in a Keplerian azimuthal velocity at the photosphere of a star of radius R_s and temperature T_eff, and some radial velocity. Treating the stellar photosphere as a uniform-density slab of gas, work out the post-shock temperature of the obliquely shocked gas and the timescale t for the planet to move its own diameter into the star as its azimuthal velocity slows. (I am assuming that the tau=1 distance in the stellar atmosphere is << R_p). The radiating area of the shocked gas is roughly A=2*R_p*v_phi*t (for v_phi*t < R_s), and the fractional luminosity increase from the shock-heated gas is dL=[A/(pi*R_s^2)]*[(T_shock^4/T_eff^4)-1]. Taking a maximal case of A=2*R_p*R_s, dL~(R_p/R_s)*(T_shock^4/T_eff^4) where I've assumed T_shock >> T_eff. For Earth, R_p/R_s=0.01, so the effect can be large in principle. Even if you scale back and assume A ~ R_p^2, the dependence on the fourth power of the temperature means it might be a big flash.

Next step: refine the analysis. Suppose that the planet has sunk beyond sight by the time it has lost a fraction X of its original momentum (assuming v_phi >> v_rad, then it has slowed from v_phi to (1-X)v_phi). After that time t an energy (M_p/2)*(Xv_phi)^2 has been converted into heat. Thermal energy E_th deposited by planet is 3/2 n V k_B (T_shock-T_eff) where n is pre-shock density at stellar surface and V is volume swept out by planet before it is too deep in the Sun to be seen (I am taking this to be the point at which the planet's center is at R=R_s-R_p): V = 1/2 \pi R_p^2 v_phi(1-X/2) t, so E_th = 3(1-X/2)/4 n \pi R_p^2 v_phi t k_B (T_shock-T_eff).

Equating the lost kinetic energy E_k to the gained thermal energy,
T_shock-T_eff = M_p X^2 v_phi^2 * 2 / (1-X/2)*2 n \pi R_p^2 v_phi t k_B, or roughly
T_shock-T_eff = M_p X^2 v_phi / \pi k_B n R_p^2 t, which is ~4x low for X~1.
For a Keplerian orbit at the stellar surface, v_phi=sqrt(GM_s/R_s). In that case:
T_shock-T_eff \propto M_p M_s^1/2 X^2 / R_s^1/2 R_p^2 n t.

The timescale for shocked gas to radiatively cool from T_shock to T_eff is the ratio of the deposited thermal energy to the radiative flux (~ A \sigma_SB T_shock^4):
t_cool \propto (\pi/2) n R_p^2 v_phi t k_B dT / 2 R_p v_phi t \sigma_SB T_shock^4
t_cool \propto (\pi/4) n R_p k_B dT / \sigma_SB T_shock^4 \propto R_p/T_shock^3 for T_shock >> T_eff. Ignoring conduction overestimates the length of the luminous phase. The conduction timescale depends on T_shock-T_eff, so conduction will hasten the initial dropoff in luminosity but yield a longer tail at slightly elevated luminosity.

So with E_k \propto M_p X^2 M_s / R_s (assume a Keplerian v_phi) and
t_cool \propto R_p^7 R_s^3/2 n^3 t^3 / M_p^3 M_s^3/2 X^6, the peak luminosity will be roughly E_k/t_cool, or L_peak \propto M_p^4 v_phi^5/2 X^8 / R_p^7 n^3 t^3. The more massive the planet, the brighter the flash. The faster the planet is orbiting on impact, the brighter the flash. The more momentum is dumped before the planet sinks beyond sight, the brighter the flash. The smaller the planet (at fixed mass), the brighter the flash (the same momentum is dumped into a smaller volume of the star). The shorter the timescale over which momentum/energy is transferred, the brighter the flash. (For "brighter" above read "more luminous".)

The only remaining free parameters are t and X. We need two equations involving them to eliminate them; the first is momentum conservation. The planet's initial momentum equals the total momentum of planet plus stellar gas at the point where the planet disappears from sight (the stellar gas is pushed aside, but immediately after impact has velocity ~v_phi): M_p v_phi = (M_p + mu_s n V) X v_phi
where mu_s is the mean mass per particle in the star's atmosphere and the star's rotational velocity is ignored. This becomes a quadratic equation for X which involves t: M_p = (M_p + mu_s n \pi R_p^2 \sqrt{GM_s/R_s} (1-X/2) t / 2) X.

The second equation comes from approximating the planet's trajectory as an elliptical orbit with apoapsis at R_s and velocity v_ap=(1-X/2)sqrt(GM_s/R_s) at that apoapsis. Those two parameters determine the eccentricity e:
v_ap=\sqrt{(1-e)GM_s/R_s} so (1-X/2)^2 = (1-e). Approximate t as twice the time for an object in such an elliptical orbit to move from R=R_s to R=R_s-R_p.

Given an initial guess for X, that time can be computed from equal areas in equal times + equations for the arc length and circumference of an ellipse of known e and apoapsis.

Once t is found, it can be plugged into the quadratic to yield a new value for X. The process can be iterated until (hopefully) it converges.

Knowing t and X should give you the absolute values and scalings of t_cool and L_peak, dependent only on R_p, M_p, R_s, M_s, n, mu_s, T_eff. One can also find the peak magnitude increase from -2.5*log10[(A/\piR_s^2)(T_shock/T_eff)^4]. However, some of those dependences will be non-analytic, subsumed in the estimation of t. (Complicated analytic approximations for the arc length and circumference of ellipses do exist, so complicated analytic approximations for t_cool and L_peak could be given. But my estimation of L_peak=E_th/t_cool is rather crude, so before giving complicated expressions I would improve the existing analysis. E.g. by allowing for non-negligible radial velocity [elliptical orbit from the start].)

L_peak will also have an inclination angle correction: the shocked gas will emit isotropically, but its projected area will depend on its location on the side of the stellar surface facing you. If the planet/stellar atmosphere density contrast is large enough that the length of the strip of the star's surface affected by the planet is >~ R_p, the inclination correction will get complicated.

[Possibly to be continued at some point when/if I feel like working out the numbers for an Earth analogue impacting a G2V star.]

Craters on Neutron Stars

Productive tea this morning! Productive in the sense of coming up with lots of interesting questions I don't have time to answer.

Spurred by Shri Kulkarni's colloquium on the Palomar Transient Factory yesterday, I wondered if anyone has estimated the signature of a 'death spiral' of a hot Jupiter/Neptune/(super-)Earth into its parent star. Apparently it is one idea for explaining luminous red novae: a hot Jupiter entering a giant star's atmosphere might heat up the atmosphere and create an artificial supergiant. Cool, and we know there are white dwarfs with metal in their atmospheres from disrupted asteroids. So could you detect an asteroid impact on a white dwarf? How about a neutron star? In fact, white dwarfs are fluid/gaseous, but neutron stars have a stiff equation of state... so could you get craters on neutron stars?

Tuesday, March 8, 2011

Sitting and Thinking

Friday: Looked for PHL 1811 analogs without C IV blueshifts; hard to find! Skyped with Rafiee.

Monday: Skyped with Chajet, discussion of Fine et al. style study of the dispersion in CIV linewidths due to inclination. Looked at spectra of some quasars with X-ray data but without C IV absorption. Started thinking about echo mapping of disk winds.

Tuesday: Responded to email about BAL variability at last. Skyped with Rogerson; proper weighting & treatment of paired-sightline MgII EW measurements appears ready to go. Thought more about echo mapping of disk winds and along the way thought of a minor correction we should make to our disk wind emission calculations. Nice to have the time to sit and think and follow where the thoughts go.

Thursday, March 3, 2011

The Title Goes Here

Finished review of Rafiee & Hall revised BH mass catalog paper. Finished second-pass look at PHL 1811 analog candidates & their blueshifts and absorption line properties. More going through literature. Bounced an email I shouldn't have. Looking at spectra of weak-lined, low-blueshift quasars.

Wednesday, March 2, 2011

It seemed like I did more than this today

Skype with Rogerson, Rafiee today. Quasar club. Computed blueshifts for new PHL 1811 analog candidates, and catalogued absorption redshifts. Emailed Richards about possible Chandra proposal. Began review of revised BH mass catalog paper.

Unification, Part II

Tuesday was mostly spent writing up comments on the referee's response to the PHL 1811 analogs paper, including outlining my idea for unifying them with the broader population of weak-lined quasars. Also thought and commented a bit about the X-ray C IV followup paper of Richards et al.

Monday, February 28, 2011

It's Pronounced FebRUary

Lots of going through papers and putting notes on ShareFlow over the weekend and today. Also got back into the swing of things with PHL 1811 analogs, looking over referee report and new target list.

Friday, February 25, 2011

HST Proposal Deadline Day

Talk by James Allen on Independent Component Analysis of AGN vs. star-formation contributions to galaxy spectra.
More feedback on Richards' HST COS proposal, and on Farrah's WFC3 proposal.
Short skype conversation with Rafiee.
Reading more papers for Shareflow, with some posting.

Gemini GMOS tilted slits

Posting this here for future reference, as the Gemini documentation on the issue of tilted slits is ambiguous.

Spectroscopic slits for GMOS are designed on an x-y coord system, with the dispersion direction being along the x axis. The slits are described by their tilt angle "slittilt" (in degrees, with slittilt=0 for untilted slits oriented perpendicular to the dispersion direction) and by "slitsize_x" (the width of the slit in the x direction; the resolution of the spectrum varies inversely with slitsize_x) and "slitsize_y" (the height of the slit in the y direction). Untilted slits are rectangles, but tilted slits are parallelograms, with two sides of width slitsize_x in the x direction and two tilted sides of height slitsize_y in the y direction.

* The software "gmmps" displays tilted slits as parallelograms but with the WRONG WIDTH in the x-direction (it uses slitsize_x/cos(slittilt) instead of slitsize_x).
* The document "" draws tilted slits as rectangles; that is incorrect.

Thursday, February 24, 2011


Read, thought about & commented on Richards' HST proposal and Rogerson's MNRAS paper draft.

Responded to Amy Kimball (student of Ivezic's) regarding anisotropic BELR emission.

Some reading for / posting on Shareflow.

Looked at some old candidate quasar spectra from SDSS UNKNOWN objects. Most but not all have been recovered already.

Wednesday, February 23, 2011

Ketchup Post

Have been somewhat under the weather, but what time was spent on research since my last post has been mainly spent on designing the GMOS mask for observations of the Clone Arc and galaxies nearby. Have converged except for uncertainty at Gemini about the precise shapes of tilted slits and if such slits can be placed adjacent to each other. Full discussion to be posted for future community reference when everything is finalized.

Also: Skype conversation with Jesse, read Netzer's paper for journal club, read Kollatschny & Zetzl's execrable Nature letter (solid body rotation for an accretion disk. Really?), and sent along comments on draft HST reverberation mapping proposal.

Friday, February 18, 2011

GMOS Mask Design

Today is being spent designing a multiobject slit mask for GMOS-N spectroscopy.

Thursday, February 17, 2011

Talk from Yesterday

Felt (and feel) good about the content and presentation of the talk. I have not always been conscientious about practicing my talks for the past few years, but let this post stand as a reminder (to me and my students reading this) that practice is worth it: I did two timed, out-loud run-throughs and each time I found issues that when fixed yielded substantial improvements. Practice your talk!

"Feedback from Quasar Winds (But Not Jets)"

Gzipped, tarred Keynote format

Gzipped Quicktime format (for downloading, not playing over the web)
Use up/down arrows to go forward/back through all slides except animations;
open A/V controls and use "jog shuttle" to forward/rewind thru animations.

Tuesday, February 15, 2011

Reading and Talk Prep

Day of making slides for talk, including reading and calculating needed for some.
Talk is in good shape, just needs a few final touches and an out-loud practice.

Monday, February 14, 2011

Talk Prep

Giving informal 1/2 hour talk here in Cambridge on Wednesday. The quality of talks I've seen here has been mixed (I personally am batting .500), so I want this one to be worthwhile. Being doing a lot of background reading (lots more to do though!). Prepared a nice series of slides on inhomogeneous absorption.

Friday, February 11, 2011

O VI Absorption, Talk Prep

Investigated how common narrow O VI absorption is in quasars; it's more common than I thought, but still unusual enough that yesterday's implications for PHL 1811 analogs are not overthrown.

Did a bit more preparation for my informal half-hour IoA talk next week.

Thursday, February 10, 2011


Now THAT was a good day.

PHL 1811 analogs unified with weak-lined quasars? Maybe! But even if it doesn't hold up, it made for a good research day.

Wednesday, February 9, 2011

Day of Emails

Journal club with Jesse Rogerson. Discussion of potential spectroscopic proposal related to PHL 1811 analogs; sent email to Niel Brandt regarding same.

Email to Niel Brandt and student Jianfeng Wu regarding possible improvement to Fig. 7 of our paper, and pointing out one quasar with unusually strong low-ionization emission, indicative of a soft ionizing continuum.

Emails to Niel Brandt and student Nur Filiz~Ak regarding her impressive start to studying BAL variability between SDSS Legacy and SDSS-III spectra. Suggested using Allen et al. (2011) NMF reconstructions of quasar continua.

Another, shorter email to Todd Boroson regarding quasar observables vs. fundamentals.

Emailed Laura Chajet about her latest research draft.

Tuesday, February 8, 2011

Repeat Spectra, OVI-strong BAL quasars, Observables vs Fundamentals

Weekend through Monday noonish was spent finally getting together info on repeat observations of SDSS quasars, including some (mostly from Paul Hewett) not in the DR7 quasar catalog itself. Ali Rafiee will perform PCA reconstructions of all these spectra.

Monday afternoon was spent looking in more detail at candidate O VI strong BAL quasars.

Tuesday was IoA journal club and thinking about an email from Todd Boroson. Did some simple simulations to understand how the L_observed-FWHM plane (observables) arises from the M_BH-L_bolometric plane (fundamentals). I don't think there's anything there that's obviously really puzzling; it's just complicated.

Friday, February 4, 2011

Wind and Hot Air in Cambridge

Extremely windy last night and today, but at least it's not below freezing.

I am featured on the Cambridge IoA Podcast this month.

Started creating a slide for my talk on quasar outflows and feedback a week from Wednesday that I've been thinking about for a while, to illustrate inhomogeneous covering.

Figured out how to obtain spectral resolution info from DR7 spSpec files; next step is to batch-produce this information for Ali Rafiee.

But first, am working on finishing the compiling/crosschecking of all duplicate spectra for SDSS DR7 quasars plus AGN missing from the DR7 catalog.

Short email to Jesse Rogerson with some tips for current work he's doing to turn thesis into paper.

Thought about what to do for journal club next week instead of reverberation mapping paper... decided on discussion of submitted PHL 1811 analog paper.

Thursday, February 3, 2011

Vim and Vigor

One thing I've been doing on sabbatical is to take the time to find improved solutions to common tasks I encounter. For example, I use vim (VIsual editor, iMproved) to edit text, and I've been taking the time to read the help pages to learn even more tricks. I'm finding it's definitely worth reading the help pages, even if you know a program well. On the horizon: working with svn and python.

Read and responded to Laura Chajet's latest research draft.

Gave some tips to Ali Rafiee about figuring out problematic catalog entries.

Sent comments to Yue Shen on the DR7 quasar properties catalog draft.

Lots of miscellaneous email and bookmark clearing-up.

Colloquium by Seb Oliver on HerMES (Herschel Multi-tiered Extragalactic Survey).

Started reading reverberation mapping paper for next week's journal club. And finished at 1 AM, about two hours later than I thought it was.

Wednesday, February 2, 2011

GMOS; Multiple Spectra; Risaliti and [O III]; More PHL 1811 Analogs

Too long since my last post.

* GMOS pre-imaging re-oriented, re-submitted, re-activated. We'll lose 10 minutes from the science exposures, but will still have 2 minutes' more than we asked for! Still need to take a stab at mask design.

* Started a push to cross-correlate all available, good SDSS quasar spectra with the photometric etc. info of their targets, for future reference and so Ali Rafiee can reconstruct the spectra. Progress made, but couldn't finish by self-imposed deadline, so set it aside for higher-priority project. Will return to it tonight or tomorrow.

* Risaliti et al. paper on [O III] EWs for quasar club today; a worthwhile paper.

* Monday and Tuesday and part of Wednesday was selection of more PHL 1811 analogs for next Chandra AO. Target list seems to have come together nicely, although I am now wondering again about O VI BAL quasars... which may be good for a proposal!

Thursday, January 27, 2011


Read Kormendy et al. paper for quasar journal club, then missed the Skype session. Wrote up comments and emailed them around.

Individual Skype sessions with Ali Rafiee, Laura Chajet and Jesse Rogerson.

Copied all dereddened Hewett & Wild spectra (with their redshifts in the header) to my laptop. Started adopting spectro.boss SM file to work with those spectra.

Tuesday was mostly PHL 1811 analog selection: the sequel. Men it can be done. And we have more good candidates. But the SDSS blueshifts are not trustworthy for these extreme objects, so a visual inspection stage is still required.

Received Gemini GMOS pre-imaging data for the clone arc. To my chagrin, the rotation angle is not quite optimal. Will have to consider whether to request another pre-image at a slightly different rotation angle, probably after taking a stab at mask design [there's also the issue of how well a curved slit can be faked; may need to contact Gemini about testing beta software for curved slits].

General discussion with Paul Hewett about topics of mutual interest to work on.

Monday, January 24, 2011

3C 120 and the like, redux: Death of an HST Proposal?

Continuing the last post's discussion of studying the broad-emission-line profiles of objects with known inclinations: There are a handful of "radio-intermediate quasars" which appear to be intrinsically radio-quiet quasars whose radio flux is boosted by beaming. Such objects likely have a combination of jet speeds higher than average for RQQs and jet angles to the line of sight smaller than average for RQQs, but for any significant boosting factor, small inclination angles i<20 are needed to distinguish them from unbeamed RQQs, as seen in
Figure 13.9 here.

If such objects show disk-wind dominated BELR dynamics, they should have large C IV blueshifts relative to Mg II. But only 2 of 5 objects do:

3C 120 : redshift 104 +- 9 km/s
III Zw 2 : redshift 100 +- 100 km/s
PG 1309+355 : redshift 220 +- 10 km/s (slight uncertainty due to assoc. C IV abs.)
PG 2209+184 : blueshift 1000 +- 50 km/s
PG 1407+263 : blueshift 4430 +- 1340 km/s

So... unsurprisingly, things are more complex than simple inclination dependence of line profiles. Small inclinations and large blueshifts are not interchangeable.

So my enthusiasm for proposing for HST spectra of gamma-ray NLS1s has decreased. But not vanished - if the above objects' line profiles (and the optical line profiles of the gamma-ray loud NLS1s) can be understood as resulting from the combined effects of inclination, radio-loudness and Eddington ratio (e.g., intermediate or high L/Ledd may quench radio jets present at other L/Ledd values; Churazov et al. 2005MNRAS.363L..91C), then an HST proposal would be well-motivated.

Sunday, January 23, 2011

3C 120 and the like

Dereddened DR7 quasar spectra for Ali Rafiee.

Outlined steps to improve selection of PHL 1811 analogs.

Posted comments on a paper on shareflow.

Downloaded and coadded IUE spectra of 3C 120 as a test of what quasar spectra look like at 20.5+-1.8 degrees from face-on (as determined by the radio jet orientation; Jorstad et al 2005). C IV peak is redshifted by ~104 km/s relative to Mg II peak (assuming 1:1 doublet ratios in both lines). Naively I would have expected C IV to be blueshifted. (Mg II is blueshifted by 261 km/s from NED redshift, but within the uncertainties/systematics all three redshifts are probably consistent.) So it may be that in radio-loud quasars the disk wind is suppressed, which means that studying the emission-line profiles of RLQs where you know the inclination doesn't tell you anything about RQQs at similar inclinations. Problematic for my idea of an HST proposal for gamma-ray loud NLS1s. But I can still try and see what disk wind parameters at inclination i=20 do and do not match the 3C 120 C IV line profile; the results may be interesting.

Another approach to studying the line profiles of objects with known inclinations would be to turn to the handful of radio-quiet/intermediate quasars known or thought to have superluminal motion. Such objects may still show disk-wind dominated dynamics, and their beamed nature means they're likely close to the line of sight.* There are 4 such RIQs (beamed RQQs), the 1st 2 of which have confirmed superluminal motions:
PG 1407+263, Blundell et al. 2003ApJ...591L.103B [known to have large blueshifts];
III Zw 2, 1996ApJ...473L..13F & 2000A&A...357L..45B (though i<41 there was overruled by 2005 paper) & 2005A&A...435..497B;
PG 1309+355, 1996ApJ...473L..13F;
PG 2209+184, 1996ApJ...473L..13F.
There is HST y/o IUE data on all of these, at which I'm starting to take a look.

* Caveat: need to keep in mind that beaming depends very much on jet velocity as well as angle to the line of sight. It may be that RIQs are the subpopulation of RQQs with the highest jet speeds, rather than the subpopulation seen at very small angles to the jet.

Friday, January 21, 2011

Three Days

Wednesday was quasar journal club. Worked a bit more on plotting results of Davis & Agol inhomogeneous accretion disk, but haven't finished it yet.

Thursday was colloquium by Vivienne Wild, and colloquium dinner, and some science discussion, and sorting old science/project notes of my own.

Friday I finished assembling information on duplicate spectra of SDSS DR7 quasars for Ali Rafiee.

Tuesday, January 18, 2011

Two Days

Updated installations of skycat, GEMINI and other IRAF packages, plus APT and gmmps. Got copy/paste working between terminal/xterm, and xterm/xgterm, but not between terminal/xgterm.

Obtained and checked HST imaging data to help in Clone lens mask design.

Skype chats with students L. Chajet and J. Rogerson.

Some writeups/postings on papers for Shareflow.

Finished writing sm code for size of Dexter & Agol inhomogeneous accretion disk; that is, radius which encloses X% of the light at wavelength Y.

Friday, January 14, 2011

Friday Fun

Gave presentation to ~9 IoA members interested in extragalactic astronomy. Covered Jesse Rogerson's Mg II absorber work, our Gemini proposal, and the disappearing FeLoBAL troughs in FBQS J1408+3054.

Read papers on microlensing studies of quasar BELRs, among other topics.

Thursday, January 13, 2011

Thursday the 13th!

Finished my end of Gemini Phase II; turns out I need to get an OK for adding an hour angle constraint, so I await word on that. One lesson learned is that there are lots of complexities to using curved slits at fixed angles on the sky to get spectra of gravitationally lensed arcs; IFUs on 30-meter class telescopes will make these observations much simpler someday [more compact lenses can be done now with IFUs on 8-meter class telescopes, but aren't as useful for the application I have in mind].

Did a 10-15 minute interview for an Institute of Astronomy podcast that should appear next month.

Worked on my informal presentation for tomorrow's extragalactic gathering.

Wed. Jan. 12

Did a bit more work on Gemini Phase II, but primarily worked on PHL 1811 analogs, mostly on figuring out how many narrow-line C IV absorbers they have as compared to expectations for quasars in general.

Tuesday, January 11, 2011

Blogging Anew!

First real day back at work (now at the Institute of Astronomy in Cambridge, UK).
Sent off reference letters for former student & current postdoc Ali Rafiee.
Worked on Gemini Phase II planning for spectroscopy of a giant arc.