Past Events in 2018

Non-Zeeman Circular Polarization of Rotational Molecular Spectral Lines

Date: 
Wednesday, April 04, 2018 - 3:30pm PDT
Speaker: 
Martin Houde
Affiliation: 
University of Western Ontario
Location: 
N232 R103
Event Type: 
Colloquium

In this presentation I will discuss the recent discovery of circular polarization signals in the rotational line profiles of molecules that are negligibly sensitive to the Zeeman effect. Our initial findings obtained for CO in the Orion KL star-forming region with the Caltech Submillimeter Observatory were followed with similar detections for two transitions of CO in an exhaustive study of the supernova remnant IC 443 (G), obtained with the IRAM 30m.

New Cosmological View of Dark Matter, which Strangely and Slowly Decays

Date: 
Tuesday, April 10, 2018 - 3:30pm PDT
Speaker: 
Sir Roger Penrose
Affiliation: 
Oxford
Location: 
N201
Event Type: 
Colloquium

Sir Roger Penrose will give a talk on his latest research and provide an insight into the thinking of a modern day theoretical physicist. Is the Universe destined to collapse, ending in a big crunch or to expand indefinitely until it homogenizes in a heat death? Roger will explain a third alternative, the cosmological conformal cyclic cosmology (CCC) scheme – where the Universe evolves through eons, each ending in the decay of mass and beginning again with new Big Bang.

Interstellar Dust Grain Alignment - Current Status

Date: 
Wednesday, April 11, 2018 - 9:00am PDT
Speaker: 
B-G Andersson
Affiliation: 
NASA Ames, SOFIA Science Center
Location: 
N/A
Event Type: 
Teletalk

Although interstellar polarization has been known for almost 70 years (and emission polarization, in the FIR, since 1982), it is only relatively recently that a quantitative, empirically tested, theory has been developed. This “Radiative Alignment Torque (RAT) theory” predicts that paramagnetic dust grains align if exposed to an anisotropic radiation field, with wavelengths less than the grain diameter.  For strong radiation fields, RAT theory predicts that the alignment can become aligned with the radiation direction.

Cold cloud formation and evolution with 21-SPONGE and GASKAP

Date: 
Wednesday, April 11, 2018 - 3:30pm PDT
Speaker: 
Snezana Stanimirovic
Affiliation: 
University of Wisconsin Madison
Location: 
N232 R227
Event Type: 
Colloquium

Cold interstellar clouds are a necessary step on the way to star formation. Yet, understanding how these clouds form out of the warm diffuse medium, and what fundamental processes regulate their atomic and molecular fractions, has been largely unexplored. We have recently completed the first statistical study of the properties of neutral gas over the entire temperature range 10-104K. This project, "21 cm Spectral Line Observations of Neutral Gas with the (E)VLA" (21-SPONGE), is a large (58 lines of sight) survey of Galactic HI absorption with the Karl G. Jansky Very Large Array.

Observing Cool Dust Around Active Galactic Nuclei Using the SOFIA Telescope

Date: 
Wednesday, April 18, 2018 - 9:00am PDT
Speaker: 
Lindsay Fuller
Affiliation: 
University of Texas at San Antonio
Location: 
N/A
Event Type: 
Teletalk

Dust surrounding supermassive black holes (SMBHs) in active galactic nuclei (AGN) intercepts optical and UV radiation from the center and reradiates in midinfrared (MIR) wavelengths. Observed differences in AGN properties are largely explained by a toroidal distribution this surrounding dust, blocking direct view of the center in some lines of sight.

AGN, SOFIA and Next Gen Telescopes

Date: 
Wednesday, April 18, 2018 - 3:30pm PDT
Speaker: 
Chris Packham
Affiliation: 
University of Texas at San Antonio
Location: 
N232 R227
Event Type: 
Colloquium

It is observationally well known that supermassive black holes (SMBHs, ≥106 Mo) are ubiquitous in galaxy centers, and the masses of SMBHs and galaxy stellar components are tightly correlated.  This suggests that SMBHs and galaxies co-evolved and that SMBHs play an important role in galaxy formation.  AGN (active galactic nuclei) are the primary objects in these studies as they are accreting surrounding gas and exchanging gravitational potential energy to produce copious amounts of heat and thermal radiation.

OPAL: HST's View of Atmospheric Evolution

Date: 
Wednesday, April 25, 2018 - 3:30pm PDT
Speaker: 
Mike Wong
Affiliation: 
UC Berkeley
Location: 
N232 R103
Event Type: 
Colloquium

Time-domain data provide a distinct approach for making discoveries about how the atmospheres of the outer planets function. Key areas of study are heat transport, atmospheric structure and evolution, composition, the formation of clouds and hazes, and comet/asteroid impacts.

Through the Eye of the Storm: Experiencing hurricane MARIA at Arecibo Observatory before, during and after its passage.

Date: 
Wednesday, May 02, 2018 - 3:30pm PDT
Speaker: 
Gerrit Verschuur
Affiliation: 
Astronomer Emeritus, Arecibo Observatory
Location: 
N232 R103
Event Type: 
Colloquium

Dr. Gerrit Verschuur (radio astronomer) will present an illustrated eyewitness account of the passage of the eye of Hurricane MARIA (Category 4) as it passed over the Observatory, where several staff members sheltered during the storm.  As many as one thousand died in the aftermath and today the consequences of MARIA still affect life at the observatory and in the town of Arecibo. The talk will reveal a dramatic discovery concerning the nature of interstellar neutral hydrogen structure that was made because hurricane MARIA created the necessary opportunity.

On-Chip spectrometers for future submm-wavelength MOSes and IFUs

Date: 
Wednesday, May 09, 2018 - 3:30pm PDT
Speaker: 
Erik Shirokoff
Affiliation: 
University of Chicago
Location: 
N232 R227
Event Type: 
Colloquium

SuperSpec is an ultra-compact spectrometer-on-a-chip for mm and submm wavelength astronomy.  Its very small size, wide spectral bandwidth, and highly multiplexed detector readout will enable construction of powerful multi-object spectrometers optimized for observations of large numbers of high-redshift star-forming galaxies, intensity mapping experiments, and sensitive, wide-area maps of the local universe.  SuperSpec employs a filter bank consisting of planar, lithographed superconducting transmission line resonators.

Infrared properties of nitrogen-included carbonaceous compounds

Date: 
Tuesday, May 15, 2018 - 3:00pm PDT
Speaker: 
Izumi Endo
Affiliation: 
University of Tokyo
Location: 
N232 R227
Event Type: 
Seminar

The unidentified infrared bands (UIR) bands have been observed ubiquitously in various astrophysical environments. Polycyclic aromatic hydrocarbon (PAH) hypothesis is commonly used to interpret the behavior of the observed UIR bands, however, our knowledge on the true carriers of the UIR bands is still limited. We have synthesized Nitrogen-included Carbonaceous Compounds (NCC) by exposing hydrocarbons (e.g., Quenched Carbonaceous Composite; QCC and/or PAHs) to nitrogen plasma via 2.45 GHz microwave discharge.

Terahertz Astronomy from Near Space and Beyond

Date: 
Wednesday, May 16, 2018 - 3:30pm PDT
Speaker: 
Christopher Walker
Affiliation: 
University of Arizona
Location: 
N232 R103
Event Type: 
Colloquium

With the advent of ultralong duration ballooning and new innovative approaches to CubeSats and large space based telescopes, the prospects are bright for a new generation of powerful terahertz observatories. To reach their full potential these observatories will push beyond the boundaries of current technology, necessitating advancements in detector and telescope design. During the presentation plans and concepts for this new generation of terahertz observatories will be discussed.

The Interaction of Cosmic Rays with Molecular Clouds in the Galactic Center

Date: 
Thursday, May 17, 2018 - 3:30pm PDT
Speaker: 
Farhad Yusef-Zadeh
Affiliation: 
Northwestern University
Location: 
N232 R152
Event Type: 
Seminar

The ISM in the inner few hundred pc of the Galactic center differs from elsewhere in the Galaxy. This region is centered on a 4 million supermassive black hole and is occupied by a large concentration of molecular gas with high column density, high velocity dispersion and high gas temperature. Recent IR and X-ray observations indicate that the cosmic ray ionization rate is higher than elsewhere in the Galaxy by one to two orders of magnitudes.

The Inception of Star Cluster Formation Revealed by [CII] Emission Around an Infrared Dark Cloud

Date: 
Wednesday, May 23, 2018 - 9:00am PDT
Speaker: 
Thomas Bisbas
Affiliation: 
University of Florida
Location: 
N/A
Event Type: 
Teletalk

We present SOFIA-upGREAT observations of [CII] emission of Infrared Dark Cloud (IRDC) G035.39-00.33, designed to trace its atomic gas envelope and thus test models of the origins of such clouds. Several velocity components of [CII] emission are detected, tracing structures that are at a wide range of distances in the Galactic plane. We find a main component that is likely associated with the IRDC and its immediate surroundings.

Microchannel Plate UV Detector Technology Development: Past Mission Implementations and Prospects for the Future

Date: 
Wednesday, May 23, 2018 - 3:30pm PDT
Speaker: 
Oswald Siegmund
Affiliation: 
UC Berkeley/SSL
Location: 
N232 R103
Event Type: 
Colloquium

Ultraviolet detection through the use of microchannel plate based photon counting imaging detector systems has been extensively implemented over the past 30 years for many NASA missions. These span implementations in Astrophysics (EUVE, ALEXIS, COS HST, GALEX, FUSE, ORFEUS-ASTROSPAS, FAUST, CHIPS, SPEAR, and many sub-orbital missions), Solar Physics (SOHO, Solar Orbiter, and rockets such as EUNIS and SERTS), Earth Observation and Aeronomy (GOLD, ICON, IMAGE, SSULI, SUSSI, GUVI), and Planetary Science (ROSETTA, New Horizons Pluto, LRO, JUNO, JUICE, EUROPA, EMM).

Unveiling the Remarkable Photodissociation Region of M8

Date: 
Wednesday, June 13, 2018 - 9:00am PDT
Speaker: 
Maitraiyee Tiwari
Affiliation: 
MPIfR
Location: 
N/A
Event Type: 
Teletalk

Messier 8 (M8), the Lagoon Nebula, has one of the brightest HII regions and photodissociation regions in the sky, located in the Sagittarius-Carina arm, near our line of sight towards the Galactic Center. We present the bright fine structure lines of [CII], [CI] and multiple rotational transitions of CO observed towards the HII region and the PDR in M8 using SOFIA, IRAM 30 m and APEX telescopes.

New Observational Views on the Chemistry of Diffuse Interstellar Clouds

Date: 
Wednesday, June 27, 2018 - 9:00am PDT
Speaker: 
Helmut Wiesemeyer
Affiliation: 
MPIfR
Location: 
N/A
Event Type: 
Teletalk

Since more than two decades, various space and airborne instruments for far-infrared spectroscopy deliver insights, unobtainable any other way, into the chemistry of the interstellar medium. The reactants and products of the reaction network forming astrophysical hydrides are meanwhile identified by observations, even some key species only recently.

Infrared Observations of Novae in the SOFIA Era: Update

Date: 
Wednesday, July 11, 2018 - 9:00am PDT
Speaker: 
Bob Gehrz
Affiliation: 
University of Minnesota
Location: 
N/A
Event Type: 
Teletalk

Classical novae may contribute to some of the isotopic anomalies that are present in the remnants of the primitive solar system. We describe the way infrared (IR) photometric and spectroscopic observations can quantify the physical parameters of nova explosions and their contributions to the Inter-Stellar Medium (ISM). Metal abundances in the ejecta can be deduced from both IR dust emission features and forbidden line emission. We show that some novae have produced ejecta extremely overabundant in CNO, Ne, Mg, Al, and Si.

Feedback from Massive Stars: SOFIA Observations of the Horsehead, W43, and the CMZ

Date: 
Wednesday, July 18, 2018 - 9:00am PDT
Speaker: 
John Bally
Affiliation: 
University of Colorado
Location: 
N/A
Event Type: 
Teletalk

Feedback from stars plays a fundamental role in regulating the rate of star formation and in shaping the interstellar medium. Although low mass stars are far more numerous, massive star feedback in the form of soft and ionizing UV, powerful stellar winds, and supernovae, dominate the energy and momentum injection budget of the Galaxy. In this talk I will review recent observations of three environments with progressively larger feedback impacts.

The Dust and Cloud Distribution of the Torus of NGC 1068

Date: 
Wednesday, August 01, 2018 - 9:00am PDT
Speaker: 
Enrique Lopez Rodriguez
Affiliation: 
SOFIA Science Center
Location: 
N/A
Event Type: 
Teletalk

The 8-13 microns (mid-IR) spectral range has proven to be exceptionally rich in spectral features that can be used to characterize the dust emission properties of active galactic nuclei (AGN). At longer wavelengths (> 20 microns), the moderate angular resolution (>10 arcsec) observations available by space-based telescopes have made the characterization of nearby AGN very challenging.

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