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Astro Lunch Talks

Astro Lunch Talks
Wednesdays, 11:45am-1:00pm, 76-1275 Carlson Learning Center.
Topics will be emailed prior to the talk. Please contact Ben Sargent for more information. 
 
Upcoming Talk Details
Date/Time: October 1, 12:00pm 76-1275
 
Speaker: Kristina Punzi
Title: An Unbiased Radio Emission Line Survey of the Protoplanetary Disk Orbiting LkCa 15
Abstract:We have conducted a comprehensive mm-wave molecular emission line survey of the circumstellar disk orbiting the nearby, pre-main sequence (T Tauri) star LkCa 15 (D = 140 pc).
The outer disk (>30 AU) orbiting this young (∼ 2-5 Myr), actively accreting solar analog is chemically rich, with numerous previous detections of molecular emission lines revealing a significant gas mass. The inner (<30 AU) disk may host a young protoplanet (LkCa 15b) within its central cavity. Hence, LkCa 15 is an excellent target for an unbiased radio spectroscopic survey intended to produce a full census of the detectable molecular species within an evolved, protoplanetary disk. Our survey of LkCa 15 was conducted with the Institute de Radioastronomie Millim ́etrique (IRAM) 30 meter telescope over the 210-270 GHz (1.4 - 1.1 mm) range. We find that lines of 12CO, HCO+, HCN, 13CO, CN, C2H, CS, H2CO, and C18O constitute the strongest molecular emission from the LkCa 15 disk in the spectral region surveyed. The survey includes complete coverage of the CN and C2H hyperfine complexes. Modeling of these CN and C 2 H hyperfine complexes indicates that these molecules either reside in coldest regions of the disk or are subthermally excited and their abundances are enhanced relative to molecular clouds and young stellar object environments. These results highlight the need for interferometric observations and the importance of properly accounting for high-energy (FUV and X-ray) radiation from the central T Tauri star in models of protoplanetary disks to distinguish between possible molecular abundance enhancement and emitting region scenarios. Thus, this work demonstrates the value of comprehensive single-dish line surveys in guiding future high resolution interferometric imaging by the Atacama Large Millimeter/submillimeter Array (ALMA) of protoplanetary disks orbiting T Tauri stars.
 
2014-2015 Academic Year Scheduled Dates
Date Speaker Title
8/20/2014
Yasaman Yazdi
Firewall Phenomenology with Astrophysical Neutrinos
9/3/2014
Adrian Hamers
Secular dynamics of hierarchical quadruple systems
9/17/2014
Andy Lipnicky
Exploring the Effects of Dwarf Galaxies on HI Disks
9/19/2014
Dennis Bowen
Simulating Binary Black Holes in their Astrophysical Environment
9/24/2014
Triana Almeyda
Modeling the Reverberation Response of the Dusty Torus Emission from AGN
10/1/2014
Kristina Punzi
An Unbiased Radio Emission Line Survey of the Protoplanetary Disk Orbiting LkCa 15
10/29/2014
TBA
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11/5/2014
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11/19/2014
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12/3/2014
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12/172014
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1/28/2015
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2/4/2015
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2/18/2015
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3/4/2015
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3/18/2015
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4/1/2015
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4/15/2015
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4/29/2015
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5/6/2015
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Past Talks


Date Speaker Title
8/6/2014 Bernard Schutz Prospects for the first gravitational wave detections
7/30/2014 Stefi Baum The Jansky Very Large Array Community Sky Survey
7/23/2014 Wolfgang Steffen Shape - an interactive astrophysical laboratory
7/16/2014 Billy Vazquez SPITZER MID INFRARED REVERBERATION LAG MEASUREMENTS OF SEYFERT NGC 6418
5/14/2014 Luc Blanchet Recent developments on post-Newtonian computations of compact binary inspiral
4/16/2014 Valerie Rapson A Spitzer and Herschel Study of the Protoplanetary Disk Around the Young Nearby System V4046 Sgr
4/10/2014 Beverly Berger Expanding $T^2$-Symmetric Vacuum Cosmological Spacetimes
3/19/2014 Davide Lena Gas kinematics within 300 pc from the nucleus of the Seyfert galaxy NGC 1386
3/5/2014 AST Panel Alternative Career Path Panel Discussion
2/19/2014 Jennifer Connelly Challenging Groupthink: Global Properties and Population Exploration of X-ray & Optically Selected Groups at 0.1<z<0.8
2/5/2014 David Merritt Planar satellite structures in the Local Group and their compatibility with ΛCDM
12/4/2013 Joel Kastner & Marcus Freeman Some (Highly Biased) Highlights from the Asymmetrical Planetary Nebulae VI Conference: Planetary Nebula Shaping & X-rays
11/20/2013 Mihail Barbosu Dynamics of a Spacecraft in a Photo-Gravitational Field
10/23/2013 Jake Noel-Storr Communicating Astronomy with the Public
10/19/2013 Dave Principe Multiwavelength Observations of the Nearby, pre-Main Sequence Binary TWA 30
9/25/2013 Billy Vazquez NGC 6148, an AGN outside the Unified Scheme?
9/18/2013 Dmitry Vorobiev Polarimetry With Microgrid Polarizer Arrays:Simulation, Fabrication and Characterization of Polarization-Sensitive Focal Planes
9/11/2013 Christopher O'Dea The Labors of Hercules A: Trying to Make Sense of a Complicated Radio Galaxy
8/21/2013 Rudy Montez X-ray Emission from Central Stars of Planetary Nebulae: Surviving in a Photon Starved Environment
8/7/2013 Sravani Vaddi Overview of Astrostatics Workshop