Sun Valley, Idaho
20 – 24 August 2017
Thursday, 24 August 2017
12:15 PM – 1:30 PM Mountain Time
Boiler Room
The Gamma-ray SIG Town Hall will be held at the 16th HEAD Meeting on Thursday, August 24th, from 12:15 to 1:30 P.M. Attendees are encouraged to bring food and have lunch during the presentations.
We will start the session with a 5 – 10min presentation on the organizational plan for GammaSIG. We will then feature three 15 minute (+ questions) talks reporting: 1) the recent polarization results collected with the Compton Spectrometer and Imager (COSI); 2) the Transient Astrophysics Probe (TAP) observatory selected as a NASA probe mission concept; and 3) the All-sky Medium Energy Gamma-ray Observatory (AMEGO) concept, which proposes to cover the largely unexplored energy range from 200 keV to 10 GeV, with polarization capabilities below 3MeV.
| Topic | Exploring Astrophysical Gamma Ray Polarization with COSI |
|---|---|
| Speaker | Steve Boggs / UC Berkeley |
| Abstract | Abstract: Astrophysical polarization measurements provide unique diagnostics for determining emission mechanisms and source geometries (e.g., magnetic field, accretion disk, and jet), but current gamma-ray results give just a glimpse into the potential for what we can learn. The Compton Spectrometer and Imager (COSI) wide-field gamma-ray telescope (0.2–5 MeV) is designed to perform pioneering studies of gamma-ray polarization. Compton telescopes are inherently sensitive to linear polarization. Compact designs (like COSI vs. COMPTEL) maximize the efficiency for detecting photons scattered at ~90° which are the most highly modulated, resulting in excellent sensitivity to polarization. COSI underwent a successful 46-day science flight in 2016 on NASA's 18 MCF superpressure balloon, the first science payload to launch from New Zealand. During the flight, COSI detected several sources for which polarization measurements are feasible, including the bright, long-duration gamma-ray burst GRB 160530A. I will discuss the polarization performance, polarization analysis results for GRB 160530A, and the future polarization goals for the COSI program. |
| Topic | Transient Astrophysics Probe (TAP) |
|---|---|
| Speaker | Judith Racusin/NASA Goddard Space Flight Center |
| Abstract | Abstract: The TAP mission will explore the transient high-energy Universe using a suite of 4 instruments to survey the sky in the soft X-ray band with the Wide Field Imager (WFI) and gamma-ray band with the Gamma-ray Transient Monitor (GTM). TAP will rapidly follow-up new transient sources with the sensitive X-ray Telescope (XRT) and near-InfraRed Telescope (IRT). TAP is optimized for localizing and characterizing counterparts to gravitational wave sources detected by both ground and space-based gravitational wave detectors. TAP will also discover and monitor transient and variable sources including gamma-ray bursts, tidal disruption events, supernovae, novae, active galaxies, and other Galactic and extragalactic sources. TAP is currently under study as a NASA probe mission concept, and will be submitted to the 2020 Decadal Survey for consideration to fly in the late 2020s. |
| Topic | All-Sky Medium Energy Gamma-ray Observatory (AMEGO) — A Discovery Mission for the MeV Gamma-ray Band |
|---|---|
| Speaker | Julie McEnery/NASA Goddard Space Flight Center |
| Abstract | Abstract: The MeV domain is one of the most underexplored windows on the Universe. From astrophysical jets and extreme physics of compact objects to a large population of unidentified objects, fundamental astrophysics questions can be addressed by a mission that opens a window into the MeV range. AMEGO is a wide-field gamma-ray telescope with sensitivity from ~200 keV to >10 GeV. AMEGO provides three new capabilities in MeV astrophysics: sensitive continuum spectral studies, polarization measurements, and nuclear line spectroscopy. AMEGO will consist of four hardware subsystems: a double-sided silicon strip tracker with analog readout, a segmented CZT calorimeter, a segmented CsI calorimeter and a plastic scintillator anti-coincidence detector, and will operate primarily in an all-sky survey mode. In this presentation we will describe the AMEGO mission concept and scientific performance. |