Astro Journal Club at Drexel

* Tuesdays, 2 - 3 p.m. * * Disque Hall, Rm 808 *

Winter 2007:
This term's topic
Planets and Brown Dwarfs

General Format: We will have usually one talk aimed to last 20 to 30 minutes, followed by discussion within the group. Presentations should be prepared in the usual colloquium format, e.g., power point. When the speaker announces a reference paper, please make the effort to read it in advance so that we can all actively participate in the parley. An obvious place to look for potential papers remains:

http://xxx.lanl.gov/archive/astro-ph

We also strongly encourage students to become familiar and search the ADS astronomy page for articles that are already published, and thus peer reviewed, at:

http://adsabs.harvard.edu/abstract_service.html

* We might also have external speakers this quarter, and the schedule below will be updated as information becomes available.

Winter 2007: Tuesdays, 2 pm, cookies and tea will be there as well.

A list of "in charge" discussion leaders/speakers will be updated weekly and can be found here:

Date Speaker
January 16th
no internal speaker; see talk by
Richard Stallman (see here for info)

January 23rd
John Parejko
1) short (~10 min) talk on his recent work on cross-matching the SDSS galaxy sample with other surveys that cover the sky in various other wavelengths,
and,
2) highlights of the Seattle AAS Meeting.

January 30th
external speaker
Anna Sajina , Spitzer Science Center
Title: Decomposing IRS spectra of z~1-3 ULIRGs
Abstract: I will present results on mid-IR spectal decomposition of a set of 48 Spitzer-selected ultraluminous infrared galaxies (ULIRGs) at z~1-3. ULIRGs are the result of major mergers which drives both extreme star-formation and black hole accretion. They are believed to have evolved strongly between the observed epoch and today, and are a major contributor to the SFR density at z~2. They might also be related to the luminous quasars whose number density peaked at z~2. Our study aims at a better understanding of the processes behind the strong evolution observed between z~2 and today. Diagnostic diagrams are used to quantitatively separate the relative contribution of star-formation and AGN activity to the mid-IR spectra of our sources. The relationship of our sample with other high-z ULIRG populations (such as SCUBA galaxies) is also discussed.

February 5th
external speaker
Rajesh Deo, Georgia State Univ.

Title: Spitzer/IRS Observations of Seyfert 1.8-1.9 Galaxies.
Abstract: I will present a study of Spitzer/IRS mid-infrared spectra of Seyfert 1.8 and 1.9 galaxies, focusing on comparison of mid-IR spectral properties of Seyfert 1.8-1.9s with those of Seyfert 1s and Seyfert 2s. In the framework of the Unified Model of Seyferts, Seyfert 1.8-1.9 nuclei are considered to be intermediate in viewing angle to the central source, Seyfert 1s being viewed mostly pole-on, while Seyfert 2s being viewed mostly edge-on. A dusty torus-like obscuration, in the equatorial plane, hides the broad-line region from the view for Seyfert 2s. The differences in the optical spectra of Seyfert galaxies arising due to purely geometrical effect of the viewing angle to the central continuum source. Seyfert 1.8-1.9 nuclei show weak broad wings on the H_beta and H_alpha lines in their optical spectra. These nuclei are also considered to be transitioning systems, in the sense that their optical spectrum can change from a Seyfert 1 like spectrum (dominated by broad and narrow lines) to a Seyfert 2 like spectrum (showing only narrow lines) and vice-versa in a span of few years. It has been observed that the variations in H_beta and H_alpha line fluxes are correlated with changes in the intrinsic line of sight reddening to these objects, implying a moving dust screen between the broad-line region and the narrow-line region. In the context of the Unified Model, this dust screen could possibly be the edge of the putative dusty torus. If so, it would be possible to constrain the properties of the putative torus in these systems. Toward this goal, I present the mid-IR spectral diagnostics of a sample of 67 Seyfert 1s, 2s and 1.8-1.9s and discuss some implications.
February 6th
external speaker
Jeff Van Duyne, Yale Univ.

Title: Spitzer Observations of Obscured AGN in GOODS: Stealthy Workhorses of SMBH Growth and Galaxy Evolution
Abstract: The Spitzer Space Telescope has begun to lift the veil on many aspects of obscured active galactic nuclei and ULIRGs. Much of the current work has focused on the most luminous sources such as the extremely powerful and heavily obscured QSO2s, and X-ray quiet AGN candidates with IR power-laws. The focus of this talk, however, will involve thesis work detailing the mid-IR properties of run-of-the-mill, Seyfert-like obscured AGN with luminosities in the range of L_X=1042-44.5 erg/s, at intermediate redshifts (0.5
February 13th
Danny Pan

Detecting Extrasolar Planets

a broad and brief introduction into a couple of the proposals and papers on extrasolar planets and finding them with PlanetQuest and SIM.
based on info from: http://planetquest.jpl.nasa.gov/SIM/sim_team.cfm

February 20th
Michael French

astro-ph/0608298 [abs, ps, pdf, other] :
Title: Extrasolar Planets: A Galactic Perspective
Authors: I. N. Reid
Comments: to appear in "A Decade of Extrasolar Planets around Normal Stars", the 2005 STScI May Symposium

February 27th
Michael Kaczmarczik
astro-ph/0608417 [abs, pdf] :
Title: Planetesimals To Brown Dwarfs: What is a Planet?
Authors: Gibor Basri, Michael E. Brown (Univ. of California, Berkeley and California Inst. of Technology)
Journal-ref: Ann.Rev.Earth Planet.Sci. 34 (2006) 193-216

March 6th
Sanghamitra Deb
Title: "Where is the Information in Cluster Lens Reconstruction? Weak + Strong Lensing + ???"
Abstract: Combining weak and strong lensing is becoming a powerful tool for mass reconstruction of clusters. There is some concern that they are not yet optimal in the sense of using all possible strong lensing information. In particular weak + strong lensing analysis have combined image ellipticities with strong lensing positions, however no attention has been given to brightness ratio\u2019s or ellipticities of multiply images sources. There maybe a lot of information in the data which is still not used. In this talk I am going to explore the possibility of including these information in the mass reconstruction and discuss what we can gain in the process.

March 13th
Ernie Mamikonyan
Title: Planetesimals in the Presence of Giant Planet Migration
Authors: Lufkin, Graeme; Richardson, Derek C.; Mundy, Lee G.
2006ApJ...653.1464L
http://adsabs.harvard.edu/abs/2006ApJ...653.1464L

March 20th
exam week, no JClub

March 27th
Planing Session for the SDSS II Meeting at Drexel U.

====================================

Note: Penn talks that don't clash with ours will also be added FYI.
- Penn Journal Club is at 1pm on Fridays in DRL Astro Room.
Locations:

Disque 808 is found on the 8th floor of Disque Hall

DRL Astro Room is found on the 4th floor of David Rittenhouse Laboratory, on 33rd and Walnut
(DRL A2 is also in David Rittenhouse Laboratory, on 33rd and Walnut, but on the first floor)

See the home pages of Drexel and Penn for more details, maps, etc.

e-mail to: constant@drexel.edu with questions or suggestions regarding our Journal

See here for the archive of previous astro seminars.

Date	Speaker
January 16th	no internal speaker; see talk by Richard Stallman (see here for info)
January 23rd	John Parejko 1) short (~10 min) talk on his recent work on cross-matching the SDSS galaxy sample with other surveys that cover the sky in various other wavelengths, and, 2) highlights of the Seattle AAS Meeting.
January 30th	external speaker Anna Sajina , Spitzer Science Center Title: Decomposing IRS spectra of z~1-3 ULIRGs Abstract: I will present results on mid-IR spectal decomposition of a set of 48 Spitzer-selected ultraluminous infrared galaxies (ULIRGs) at z~1-3. ULIRGs are the result of major mergers which drives both extreme star-formation and black hole accretion. They are believed to have evolved strongly between the observed epoch and today, and are a major contributor to the SFR density at z~2. They might also be related to the luminous quasars whose number density peaked at z~2. Our study aims at a better understanding of the processes behind the strong evolution observed between z~2 and today. Diagnostic diagrams are used to quantitatively separate the relative contribution of star-formation and AGN activity to the mid-IR spectra of our sources. The relationship of our sample with other high-z ULIRG populations (such as SCUBA galaxies) is also discussed.
February 5th	external speaker Rajesh Deo, Georgia State Univ. Title: Spitzer/IRS Observations of Seyfert 1.8-1.9 Galaxies. Abstract: I will present a study of Spitzer/IRS mid-infrared spectra of Seyfert 1.8 and 1.9 galaxies, focusing on comparison of mid-IR spectral properties of Seyfert 1.8-1.9s with those of Seyfert 1s and Seyfert 2s. In the framework of the Unified Model of Seyferts, Seyfert 1.8-1.9 nuclei are considered to be intermediate in viewing angle to the central source, Seyfert 1s being viewed mostly pole-on, while Seyfert 2s being viewed mostly edge-on. A dusty torus-like obscuration, in the equatorial plane, hides the broad-line region from the view for Seyfert 2s. The differences in the optical spectra of Seyfert galaxies arising due to purely geometrical effect of the viewing angle to the central continuum source. Seyfert 1.8-1.9 nuclei show weak broad wings on the H_beta and H_alpha lines in their optical spectra. These nuclei are also considered to be transitioning systems, in the sense that their optical spectrum can change from a Seyfert 1 like spectrum (dominated by broad and narrow lines) to a Seyfert 2 like spectrum (showing only narrow lines) and vice-versa in a span of few years. It has been observed that the variations in H_beta and H_alpha line fluxes are correlated with changes in the intrinsic line of sight reddening to these objects, implying a moving dust screen between the broad-line region and the narrow-line region. In the context of the Unified Model, this dust screen could possibly be the edge of the putative dusty torus. If so, it would be possible to constrain the properties of the putative torus in these systems. Toward this goal, I present the mid-IR spectral diagnostics of a sample of 67 Seyfert 1s, 2s and 1.8-1.9s and discuss some implications.
February 6th	external speaker Jeff Van Duyne, Yale Univ. Title: Spitzer Observations of Obscured AGN in GOODS: Stealthy Workhorses of SMBH Growth and Galaxy Evolution Abstract: The Spitzer Space Telescope has begun to lift the veil on many aspects of obscured active galactic nuclei and ULIRGs. Much of the current work has focused on the most luminous sources such as the extremely powerful and heavily obscured QSO2s, and X-ray quiet AGN candidates with IR power-laws. The focus of this talk, however, will involve thesis work detailing the mid-IR properties of run-of-the-mill, Seyfert-like obscured AGN with luminosities in the range of L_X=1042-44.5 erg/s, at intermediate redshifts (0.5	February 13th	Danny Pan Detecting Extrasolar Planets a broad and brief introduction into a couple of the proposals and papers on extrasolar planets and finding them with PlanetQuest and SIM. based on info from: http://planetquest.jpl.nasa.gov/SIM/sim_team.cfm
February 20th	Michael French astro-ph/0608298 [abs, ps, pdf, other] : Title: Extrasolar Planets: A Galactic Perspective Authors: I. N. Reid Comments: to appear in "A Decade of Extrasolar Planets around Normal Stars", the 2005 STScI May Symposium
February 27th	Michael Kaczmarczik astro-ph/0608417 [abs, pdf] : Title: Planetesimals To Brown Dwarfs: What is a Planet? Authors: Gibor Basri, Michael E. Brown (Univ. of California, Berkeley and California Inst. of Technology) Journal-ref: Ann.Rev.Earth Planet.Sci. 34 (2006) 193-216
March 6th	Sanghamitra Deb Title: "Where is the Information in Cluster Lens Reconstruction? Weak + Strong Lensing + ???" Abstract: Combining weak and strong lensing is becoming a powerful tool for mass reconstruction of clusters. There is some concern that they are not yet optimal in the sense of using all possible strong lensing information. In particular weak + strong lensing analysis have combined image ellipticities with strong lensing positions, however no attention has been given to brightness ratio\u2019s or ellipticities of multiply images sources. There maybe a lot of information in the data which is still not used. In this talk I am going to explore the possibility of including these information in the mass reconstruction and discuss what we can gain in the process.
March 13th	Ernie Mamikonyan Title: Planetesimals in the Presence of Giant Planet Migration Authors: Lufkin, Graeme; Richardson, Derek C.; Mundy, Lee G. 2006ApJ...653.1464L http://adsabs.harvard.edu/abs/2006ApJ...653.1464L
March 20th	exam week, no JClub
March 27th	Planing Session for the SDSS II Meeting at Drexel U.