Past Events in 2017

Today's View of the Solar Neighborhood, with Emphasis on the Coldest Brown Dwarfs

Date: 
Wednesday, April 12, 2017 - 3:30pm to 4:30pm PDT
Speaker: 
Davy Kirkpatrick
Affiliation: 
IPAC/Caltech
Location: 
N232, Room 103
Event Type: 
Colloquium

Having a complete census of objects in the solar neighborhood provides a vital touchstone for studies of stellar populations in other parts of the Milky Way and in other galaxies. This talk presents an overview of how our knowledge of the census has improved over the past 100+ years. The newest members of the census, the brown dwarfs, will be briefly summarized. The core of the talk will describe a project to use the 20-pc sample to determine the functional form and low-mass cutoff of the substellar mass function.

A Pan Spectral (Theorist's) View of Star Forming Regions

Date: 
Friday, April 14, 2017 - 1:30pm PDT
Speaker: 
Gary Ferland
Affiliation: 
University of Kentucky
Location: 
N232, room 103
Event Type: 
Seminar

When it became clear that an irradiated molecular cloud, the obscuring torus, was responsible for many of the observed properties of AGN, I decided to understand what happens when ionizing radiation strikes molecular gas.  The nearest place where we can study this in detail is the Orion Nebula; M17 is the closest with a significant star cluster, and 30 Dor is the nearest starburst.  Mechanical energy from the windy star cluster forms a bubble of hot gas that constitutes the base of the resulting structure.  The optically-bright H II regions are interfaces between this hot gas and surroundin

New Insights into the Role and Importance of Interstellar Nanoparticles

Date: 
Monday, April 17, 2017 - 1:30pm PDT
Speaker: 
Thiem Hoang
Affiliation: 
Korea Astronomy and Space Physics Institute
Location: 
N232, room 103
Event Type: 
Seminar

Interstellar nanoparticles, including polycyclic aromatic hydrocarbons (PAHs), are believed to play an important role in modern astrophysics. Mid-infrared emission from PAHs is widely used as a tracer of star formation activity. PAHs is also thought to be a leading carrier behind the long-standing mystery of Diffuse Interstellar Bands.  In this talk, I will discuss new insights into the crucial importance of interstellar nanoparticles.

Gravitationally Lensed Dusty Star-Forming Galaxies at High Redshift

Date: 
Wednesday, April 19, 2017 - 3:30pm to 4:30pm PDT
Speaker: 
Eiichi Egami
Affiliation: 
University of Arizona
Location: 
N232, Room 103
Event Type: 
Colloquium

Over the last several years, discoveries of exceptionally bright gravitationally lensed dusty star-forming galaxies (DSFGs) at high redshift (z>1) have generated great excitement.  This is because these galaxies are bright enough to allow a variety of follow-up observations with the suite of submillimeter/millimeter/radio observing facilities that are now available.  Scientifically, what is particularly interesting is that these lensed DSFGs will enable us to examine individual star-forming regions on sub-kpc scales due to lensing magnification.  In this talk, I will review the developme

The NEOWISE 2017 Data Release

Date: 
Wednesday, April 26, 2017 - 3:30pm to 4:30pm PDT
Speaker: 
Roc Cutri
Affiliation: 
IPAC/Caltech
Location: 
N232, Room 103
Event Type: 
Colloquium

The Near Earth Object Wide-field Infrared Survey Explorer Reactivation mission (NEOWISE) has been scanning the sky at 3.4 and 4.6 microns since December 2013 to detect and characterize asteroids and comets and to learn more about the population of near-Earth objects that could pose a hazard.

Disk Sub-Structures Revealed by ALMA: Implications for Planet Formation

Date: 
Wednesday, May 03, 2017 - 3:30pm to 4:40pm PDT
Speaker: 
Andrea Isella
Affiliation: 
Rice University
Location: 
N232, Room 103
Event Type: 
Colloquium

The Atacama Large Millimeter and sub-millimeter Array (ALMA) has discovered sub-structures in the dust and molecular gas distributions in a number of protoplanetary disks.  These structures span spatial scales from a few to hundreds of Astronomical Units and are thought to be related to the formation of planets. During my talk I will present some of the most recent ALMA observations of sub-structures in disks and discuss them in the framework of planet formation models.

SOFIA Tomorrow: Understanding Star Formation in the Era of JWST and ALMA

Date: 
Wednesday, May 10, 2017 - 9:00am PDT
Speaker: 
Hal Yorke
Affiliation: 
USRA SOFIA
Location: 
N/A
Event Type: 
Teletalk

As SOFIA has evolved from a development project into a fully functional observatory, important advances have been made in several areas of topical astrophysical and solar system research: star formation, stellar evolution, astrochemistry, the structure and evolution of the interstellar medium in our Galaxy and external galaxies, astrophysical processes near supermassive black holes, planetary atmospheres, and moons and small bodies in the solar system science.

Astrometry.net: Recognizing Astronomical Images to Enable Science with Diverse Imaging

Date: 
Wednesday, May 10, 2017 - 3:30pm to 4:30pm PDT
Speaker: 
Dustin Lang
Affiliation: 
University of Toronto
Location: 
N232, Room 103
Event Type: 
Colloquium

I will present Astrometry.net, a computer program that takes as input an astronomical image -- from a professional telescope, scanned photographic plate, or backyard snapshot -- and determines (with no information other than the image pixels) where on the sky that image belongs, or, equivalently, identifies the stars and galaxies visible in the image.

The Production of Organics of Astrobiological Interest in Astrophysical Ices and Implications for the OSIRIS-REx Asteroid Sample Return Mission

Date: 
Wednesday, May 17, 2017 - 3:30pm to 4:30pm PDT
Speaker: 
Scott Sandford
Affiliation: 
NASA Ames
Location: 
N232, Room 227
Event Type: 
Colloquium

Infrared spectroscopy, critical portions of which have been carried out on airborne platforms, has been used to demonstrate that many astrophysical environments are dominated by mixed molecular ices.

SOFIA and Herschel Observations of Far-Infrared Fine Structure Lines from Deep Within the Galactic Center

Date: 
Wednesday, May 24, 2017 - 9:00am PDT
Speaker: 
Andy Harris
Affiliation: 
UMd
Location: 
N/A
Event Type: 
Teletalk

The Central Molecular Zone (CMZ) is the approximately 250 pc radius region at the center of our Galaxy. It contains a black hole, a large stellar bar, massive stellar clusters, and a number of the densest molecular clouds in the Galaxy (most forming stars but some not) on a variety of orbits. Our detailed understanding of structures within the CMZ is possible because of its proximity, and it is therefore a model for all normal galactic nuclei, near and far.

Recent Advances in Our Understanding of the Molecular Complexity in Astronomical Environments

Date: 
Wednesday, May 24, 2017 - 3:30pm to 4:30pm PDT
Speaker: 
Toni Remijan
Affiliation: 
NRAO
Location: 
N232, Room 103
Event Type: 
Colloquium

Over the past several years, observations of a variety of astronomical environments has led to the detection and characterization of new molecular species as well as to a better understanding of the physical and chemical conditions of these regions.  Molecular material is now found in a host of Galactic and extragalactic environments and has been used as tracers of a variety of conditions including but certainly not limited to, PDRs, XDRs, shocks, diffuse gas, dense gas, HMCs and UC HII regions.  In the era of large single dish telescopes and broadband interferometric arrays, we are truly g

The Early Stages of High-Mass Star Formation

Date: 
Wednesday, May 31, 2017 - 3:30pm to 4:30pm PDT
Speaker: 
Claudia Cyganowski
Affiliation: 
University of St. Andrews
Location: 
N232, Room 103
Event Type: 
Colloquium

Most stars form in clusters, yet basic aspects of how this occurs remain unknown, including the relative birth order of high and low mass stars. In clump-scale "competitive accretion"-type models, massive stars and their surrounding cluster of lower mass stars form simultaneously. Thus a key, testable prediction of these models is that centrally condensed low-mass cores should exist within the accretion reservoir of a forming massive star.  I will present results from an ALMA Cycle 2 program to search for low-mass cores within the accretion reservoir of a high-mass (proto)cluster.

The Inner 25 AU Debris Distribution in the Epsilon Eridani System

Date: 
Wednesday, June 07, 2017 - 9:00am PDT
Speaker: 
Kate Su
Affiliation: 
University of Arizona
Location: 
N/A
Event Type: 
Teletalk

Debris disk morphology is wavelength dependent due to the wide range of particle sizes and size-dependent dynamics influenced by various forces. Resolved images of nearby debris disks reveal complex disk structures that are difficult to distinguish from their spectral energy distributions. Therefore, multi-wavelength resolved images of nearby debris systems provide an essential foundation to understand the intricate interplay between collisional, gravitational, and radiative forces that govern debris disk structures.

A SOFIA/FORCAST Grism Study of the Mineralogy of Dust in the Winds of Proto-planetary Nebulae

Date: 
Wednesday, June 28, 2017 - 9:00am PDT
Speaker: 
Ryan Arneson
Affiliation: 
University of Minnesota
Location: 
N/A
Event Type: 
Teletalk

RV Tauri stars and SRd variable stars are post-asymptotic giant branch yellow supergiants that are believed to be the immediate precursors of planetary nebulae. I will present a SOFIA/FORCAST grism spectroscopic survey of the mineralogy of the circumstellar dust in a sample of 15 RV Tauri stars and 3 SRd variable stars. The spectra do not exhibit any prominent crystalline silicate emission features.

A SOFIA/GREAT View on the Cepheus E Outflow from an Intermediate-Mass Proto-Star

Date: 
Wednesday, July 05, 2017 - 9:00am PDT
Speaker: 
Antoine Gusdorf
Affiliation: 
MPIfR
Location: 
N/A
Event Type: 
Teletalk

Protostellar jets and outflows play a critical role in the interstellar medium (ISM) of galaxies, in which they input energy in all possible forms: mechanical through the shock waves they are associated with, far-UV photons from the protostar or from the fastest shocks, and cosmic rays (CRs) that can be locally accelerated. They hence play an important role in the ISM evolution. In this talk, I will show how SOFIA/GREAT has allowed us, since the launching of this mission, to progress in our understanding of the protostellar outflow Cepheus E driven by an intermediate mass proto-star.

The Oxygen Budget in Low-Mass Protostellar Outflows: the NGC1333-IRAS4A R1 Shock Observed in [OI] at 63 Microns with SOFIA-GREAT

Date: 
Wednesday, July 19, 2017 - 9:00am PDT
Speaker: 
Lars Kristensen
Affiliation: 
Neils Bohr Institute
Location: 
N/A
Event Type: 
Teletalk

Oxygen (O) is the third-most abundant element in the Universe after hydrogen and helium. Despite its high elemental abundance, a good picture of where oxygen is located in low-mass protostellar outflows and jets is missing: we cannot account for > 60% of the oxygen budget in these objects. This hole in our picture means that we currently do not have a good understanding of the dominant cooling processes in outflows jets, despite the fact that [OI] emission at 63 micron is one of the dominant cooling lines, nor how cooling processes evolve with protostellar evolution.

Sniffing Alien Atmospheres: Exoplanet spectrophotometry (from ground-, airborne- and space-based observatories)

Date: 
Monday, August 14, 2017 - 3:30pm PDT
Speaker: 
Daniel Angerhausen
Affiliation: 
Center for Space and Habitability (CSH), Universität Bern
Location: 
N232 R103
Event Type: 
Seminar

In my presentation I will give a short introduction to the science of extrasolar planets, in particular the technique of transit, eclipse and phasecurve spectro-photometry.  I will describe my various projects in this emerging field using state of the art spectroscopic and photometric instruments on the largest ground based telescopes, the 'flying telescope' SOFIA (Stratospheric Observatory for Infrared Astronomy) and the Kepler and Hubble space telescopes.

The SDSS/APOGEE Survey: Highlights in Galactic Chemical Evolution and Quantitative Spectroscopy of M-dwarfs

Date: 
Wednesday, September 20, 2017 - 3:30pm PDT
Speaker: 
Verne Smith
Affiliation: 
NOAO, Tucson, AZ
Location: 
N232 R103
Event Type: 
Colloquium

The Apache Point Observatory Galactic Evolution Experiement (APOGEE) is a high-resolution H-band spectroscopic survey (from 1.5-1.7µm) of hundreds of thousands of stars from all Galactic populations.  An automated analysis derives stellar parameters and detailed chemical abundance distributions based on synthetic spectral libraries computed using the APOGEE spectral line list.  The infrared (IR) spectral region at wavelengths from ~1-5µm will play an increasingly important role in future large spectroscopic surveys.  This region is ideal for using red giants to probe chemical evolution of t

First Detection of a THz Water Maser in NGC7538 IRS1

Date: 
Wednesday, September 27, 2017 - 9:00am PDT
Speaker: 
Fabrice Herpin
Affiliation: 
University of Bordeaux
Location: 
N/A
Event Type: 
Teletalk

Despite numerous water line observations obtained with the Herschel Space Observatory, observations were not able to trace the emission from the hot core around the newly forming protostellar object in most of the observed massive protostars. We hence tried to probe the physical conditions and water abundance in the inner layers of the host protostellar object NGC7538-IRS1 using a highly excited H2O line, 8_{2,7}-7_{3,4} at 1296.4 GHz. We present SOFIA  observations of the o-H2O 8_{2,7}-7_{3,4} line and a 6_{16}-5_{23} 22 GHz e-MERLIN map of the region.

Setting the Initial Conditions for Planets: The Young Circumstellar Disk

Date: 
Wednesday, September 27, 2017 - 3:30pm PDT
Speaker: 
Leslie Looney
Affiliation: 
University of Illinois
Location: 
N232 R103
Event Type: 
Colloquium

The origin and evolution of the circumstellar disk around protostars informs the origin and evolution of planets. Only recently, have we even detected the youngest circumstellar disks, but their frequency and typical properties (i.e. mass and size) are still not well known. With our new high-resolution millimeter surveys of protostars, we now have about 20 young disks with radii > 12 AU. However, these only represent less than ¼ of the population in our surveys.

Pages