Past Events in 2018

[CII] Emission from PDRs and Jet-related Shocks in the Nearby Seyfert Galaxy NGC 4258 with SOFIA

Date: 
Wednesday, August 08, 2018 - 9:00am PDT
Speaker: 
Phil Appleton/Dario Fadda
Affiliation: 
IPAC/SOFIA Science Center
Location: 
N/A
Event Type: 
Teletalk

We present the [CII] 157.7μm map of the NGC 4258 (M106) galaxy obtained with the Far Infrared Field-Imaging Line Spectrometer (FIFI-LS) spectrometer onboard SOFIA. M106 contains an active nucleus classified as type 1.9 Seyfert with a warped inner rotating disk of water-vapor masers which allowed for the first high accuracy measurements of the mass of a supermassive black hole in any galaxy.

Circumstellar Dust Shells: Clues to the Evolution of R Coronae Borealis Stars

Date: 
Monday, August 20, 2018 - 2:00pm PDT
Speaker: 
Ed Montiel
Affiliation: 
UC Davis
Location: 
N232 R227
Event Type: 
Seminar

The study of extended, cold dust envelopes surrounding R Coronae Borealis (RCB) stars began with their discovery by IRAS. RCB stars are carbon-rich supergiants characterized by their extreme hydrogen deficiency and for their irregular and spectacular declines in brightness. I have examined new and archival Spitzer Space Telescope and Herschel Space Observatory images in the far infrared and submillimeter of these envelopes to examine the morphology of these dusty shells.

HAWC+ for SOFIA: Two Years of Flying, and First Science Results

Date: 
Wednesday, September 12, 2018 - 9:00am PDT
Speaker: 
Darrin Dowell
Affiliation: 
NASA JPL
Location: 
N/A
Event Type: 
Teletalk

I first give a brief summary of instrument activities since the last HAWC+ tele-talk in January 2017, including the acceptance as a facility by NASA.  The rest of the talk focuses on the ongoing analysis and interpretation of GTO science data.  Featured topics include the fine-scale magnetic field structure of the Orion Molecular Cloud, dust grain alignment, the magnetic field in the Galactic center Circum-Nuclear Ring, and extragalactic polarimetry.

The Origins Space Telescope: A Mission Under Study for the NASA Astrophysics 2020 Decadal Study

Date: 
Wednesday, September 12, 2018 - 3:30pm PDT
Speaker: 
Tom Roellig
Affiliation: 
NASA Ames
Location: 
N232 R103
Event Type: 
Colloquium

The Origins Space Telescope (OST) is one of the four science and technology definition studies supported by NASA to prepare for the 2020 Astronomy and Astrophysics Decadal Survey. The OST is a large flagship space mission with a >6m diameter telescope cooled to roughly 6K that will undertake observations at mid to far-infrared infrared wavelengths (5 to 600 μm). At mid-infrared wavelengths (10–30 μm) OST will be a factor of 30–100 more sensitive than Spitzer and JWST, while at far-infrared wavelengths OST will offer a factor of 10,000 improvement over Herschel, AKARI, and SOFIA.

Filamentary Molecular Clouds, Star Formation, and Pristine B-Fields, as seen by SOFIA/HAWC+, Gaia DR2, and Mimir Near-IR Polarimetry

Date: 
Wednesday, September 19, 2018 - 9:00am PDT
Speaker: 
Dan Clemens
Affiliation: 
Boston University
Location: 
N/A
Event Type: 
Teletalk

Magnetic fields likely play roles in helping interstellar gas assemble into diffuse clouds and dark, molecular clouds and may play key roles in forming dense cores and the stars that form within them. But, most of the astrophysical laboratories probed for magnetic field properties are characterized by violent gas motions, ionizing radiation, stellar and disk outflows, and complex histories. Wouldn't it be nicer to peer into the earliest stages of isolated, low-mass, single star formation before all the loud music starts?

A Deeper Look at Supernovae

Date: 
Wednesday, September 19, 2018 - 3:30pm PDT
Speaker: 
Robert Kirshner
Affiliation: 
Harvard, Gordon and Bette Moore Foundation
Location: 
N232 R103
Event Type: 
Colloquium

Observations of supernova explosions are different from most astronomical observations:  The objects evolve over a human lifetime!  I will illustrate this with 3D measurements of the ejecta from SN 1987A, the brightest seen since 1604.  Observations with HST and with ALMA allow a direct comparison with models of core collapse explosions in massive stars. 

The Impact of Cloud Collisions on Star Formation

Date: 
Wednesday, September 26, 2018 - 3:30pm PDT
Speaker: 
Benjamin Wu
Affiliation: 
NAOJ
Location: 
N232 R227
Event Type: 
Colloquium

Most stars form in clusters within giant molecular clouds (GMCs). However, the processes that induce the collapse and fragmentation of GMCs into star-forming clumps are poorly understood. One potential driver of star formation activity in galactic disks may be triggering via converging molecular flows, i.e., GMC-GMC collisions. The list of cloud collision candidates is growing rapidly, but they remain difficult to observationally verify.

Massive star and cluster formation in the era of ALMA and SOFIA: comparing infrared dark cloud with Orion A

Date: 
Wednesday, October 03, 2018 - 3:30pm PDT
Speaker: 
Shuo Kong
Affiliation: 
Yale University
Location: 
N232 R103
Event Type: 
Colloquium

Star formation is crucial to the cosmos in many ways. Among the key questions in star formation, the birth of massive stars and the stellar initial mass function are the two outstanding issues to be conquered. I will introduce how we tackle the two questions in Galactic molecular clouds. Specifically, by studying in parallel two famous clouds at very different evolutionary stages, I will discuss how we can disentangle the theoretical debates on the two puzzling, yet charming, questions. This is important in understanding whether star formation is ordered or chaotic, slow or fast.

Anatomy of the Massive Star-Forming Region S106: The [OI 63] Micron Line Observed with GREAT/SOFIA as a Versatile Diagnostic Tool for the Evolution of Massive Stars

Date: 
Wednesday, October 10, 2018 - 9:00am PDT
Speaker: 
Nicola Schneider
Affiliation: 
University of Cologne
Location: 
N/A
Event Type: 
Teletalk

Observations of the major cooling lines of the interstellar medium are needed to better understand the physical processes, such as mass accretion and ejection, and feedback (thermal heating, ionization, radiation pressure, stellar winds) involved in the formation and evolution of massive stars.  For that, we observed the well-known bipolar HII region S106 in the CII 158 and [OI] 63 micron finestructure lines, and the CO 16-15, 11-10 transitions with the upGREAT instrument on SOFIA. The [OI] 63 micron emission at 6” resolution is composed of several velocity components.

Threads in the sky: Magnetic fields mapped using a “polarized” view of various star-forming regions

Date: 
Wednesday, October 10, 2018 - 3:30pm PDT
Speaker: 
Archana Soam
Affiliation: 
USRA/SOFIA
Location: 
N232 R227
Event Type: 
Colloquium

The role of magnetic fields (B-fields) and turbulence in star formation is still under debate but considering the magnetized nature of molecular clouds, we expect B-fields to have a significant impact on this process. Observations of molecular clouds in different environments using different astronomical techniques help in understanding the various important aspects of star formation. I mostly worked towards mapping B-fields in nearby low mass star forming regions in different environments viz. molecular clouds in isolation and HII regions at their different evolutionary stages.

The First Result of SOFIA-FORCAST Survey toward the Giant H II Regions - W51A

Date: 
Wednesday, October 17, 2018 - 3:30pm PDT
Speaker: 
Wanggi Lim
Affiliation: 
USRA/SOFIA
Location: 
N232 R227
Event Type: 
Colloquium

We present the first result of a large-scale SOFIA-FORCAST 20 & 37µm imaging survey toward Giant H II (GH II) regions. The high-mass stars play crucial roles on ecology of Universe, especially regarding their kinematic feedbacks and chemical inputs. The GH II regions in our Milky Way Galaxy are perfect laboratories to study the formation mechanisms of high-mass stars since they harbor most of known high-mass star forming regions on various evolutionary stages.

Study of the S1 PDR in Rho Ophiuchi: A GREAT/SOFIA View

Date: 
Wednesday, October 24, 2018 - 9:00am PDT
Speaker: 
Bhaswati Mookerjea
Affiliation: 
Tata Institute for Fundamental Research
Location: 
N/A
Event Type: 
Teletalk

Photodissociation Regions (PDRs) are manifestations of the influence of massive stars on their environment and provide us with important clues to the role of these stars in the formation of a new generation of stars. The Rho Ophiuchi dark cloud complex located at a distance of 138pc, harbors a large number of newly formed stars as well as the reflection nebula associated with the early B star S1. We studied the PDR associated with S1 using [C II] 158 micron observations with GREAT/SOFIA obtained from the SOFIA data archives.

Tracking Planet Footprints in Dusty Disks

Date: 
Wednesday, October 24, 2018 - 3:30pm PDT
Speaker: 
Catherine Espaillat
Affiliation: 
Boston University
Location: 
N232 R227
Event Type: 
Colloquium

We know that most stars were once surrounded by protoplanetary disks. How these young disks evolve into planetary systems is a fundamental question in astronomy. Observations of T Tauri stars (TTS) may provide insights, particularly a subset of TTS with “transitional disks” that contain holes or gaps in their dust disk. Many researchers have posited that these holes and gaps are the “footprints” of planets given that theoretical simulations predict that a young, forming planet will clear the material around itself, leaving behind a cavity in the disk.

Hierarchical gravitational contraction: a unified scenario for the structure, dynamics, and star-forming activity of molecular clouds.

Date: 
Wednesday, October 31, 2018 - 3:30pm PDT
Speaker: 
Enrique Vasquez Semadeni
Affiliation: 
National Autonomous University of Mexico
Location: 
N232 R227
Event Type: 
Colloquium

Diverse numerical and observational evidence suggests that star-forming molecular clouds (MCs) may be in a process of hierarchical gravitational contraction (HGC). As originally proposed by Hoyle (1953), in such a regime, a sequential destabilization of successively smaller masses should occur, leading to fragmentation of the cloud and ultimately to the formation of stellar-mass objects, when the equation of state diverts from isothermal.

Canceled

Date: 
Wednesday, November 07, 2018 - 3:30pm PST
Speaker: 
Bryan Gaensler
Affiliation: 
University of Toronto
Location: 
N232 R227
Event Type: 
Colloquium

tbd

The Earliest Stages of High-Mass Star Formation

Date: 
Wednesday, November 07, 2018 - 3:30pm PST
Speaker: 
James Jackson
Affiliation: 
USRA/SOFIA
Location: 
N232 R227
Event Type: 
Colloquium

Although the formation of low-mass stars is broadly understood, understanding high-mass star formation is much more difficult due to their rarity, their clustered environments, their short time scales, and their ability to disrupt their natal environment. I will discuss recent progress in the study of high-mass star formation. Two competing theories, “competitive accretion” and “turbulent core accretion,” make distinct quantitative predictions about the internal structure of the young, cold clumps from which stars form.

Launching Rockets from a Plane

Date: 
Tuesday, November 13, 2018 - 2:30pm PST
Speaker: 
Kelly Latimer and Zack Rubin
Affiliation: 
Virgin Orbit
Location: 
N232 R103
Event Type: 
Seminar

Kelly Latimer, Virgin Orbit’s chief pilot, along with her Flight Test Director, Zack Rubin, will give a talk about the exciting development and challenges to launching a rocket from a plane. Virgin Orbit is part of the larger Virgin Group and a sister company to Virgin Galactic. Virgin Orbit is getting ready to conduct its debut launch in the coming months.  

Polarimetry of Star Forming Regions with HAWC+: SOFIA's Important Role

Date: 
Wednesday, November 14, 2018 - 9:00am PST
Speaker: 
Judy Pipher
Affiliation: 
University of Rochester
Location: 
N/A
Event Type: 
Teletalk

Polarimetry at a variety of wavelengths and scales has become a most important diagnostic in understanding the role that magnetic fields play in the star formation process. SOFIA offers two unique perspectives. First, polarimetry from 50-240 microns probes warmer regions of the molecular cloud than do the various 850 micron ground-based polarimeters.ALMA polarimetry of the smallest spatial scales complements these FIR observations.

SOFIA/HAWC+ Detection of a Gravitationally Lensed Starburst Galaxy at z = 1.03

Date: 
Wednesday, November 28, 2018 - 9:00am PST
Speaker: 
Jingzhe Ma
Affiliation: 
Universtiy of California, Irvine
Location: 
N/A
Event Type: 
Teletalk

We present the detection at 89 μm of the Herschel-selected gravitationally lensed starburst galaxy HATLAS J1429-0028 (also known as G15v2.19) in 15 minutes with the High-resolution Airborne Wideband Camera-plus (HAWC+) onboard the Stratospheric Observatory for Infrared Astronomy (SOFIA). The spectacular lensing system consists of an edge-on foreground disk galaxy at z = 0.22 and a nearly complete Einstein ring of an intrinsic ultra-luminous infrared (IR) galaxy at z = 1.03. Is this high IR luminosity powered by pure star formation (SF) or also an active galactic nucleus (AGN)?

The MASSES Survey and Magnetic Fields in Filaments

Date: 
Wednesday, November 28, 2018 - 3:30pm PST
Speaker: 
Ian Stephens
Affiliation: 
CfA
Location: 
N232 R103
Event Type: 
Colloquium

This talk consists of two parts. The main part is about the SMA large-scale program MASSES (Mass Assembly of Stellar Systems and their Evolution with the SMA), which surveyed all 74 Class 0 and I protostars in the nearby Perseus Molecular Cloud. Low-mass stars form from the gravitational collapse of dense molecular cloud cores. The MASSES survey reveals the interplay between fragmentation, angular momentum, magnetic fields, and mass outflows in regulating accretion and setting the final masses of stars. I will overview the survey and highlight the key results.

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