Joe Michail

Joe Michail

Astronomy Ph.D. student at Northwestern University studying the radio variability of the nearest supermassive blackhole Sgr A*.

Talks and Presentations

Far-Infrared and Submillimeter Polarization Spectrum of the OMC-1 Region

January 06, 2020

Conference proceedings talk, 235th Meeting of the American Astronomical Society, Honolulu, Hawaii

We compile the most complete far-infrared multiwavelength polarization spectrum to date of the high-mass star-forming region, OMC-1, using data from the High-resolution Airborne Wideband Camera+ (HAWC+) polarimeter on the NASA / German Aerospace Center (DLR) Stratospheric Observatory for Infrared Astronomy (SOFIA). These observations are combined with ground-based polarimetry data at 350- and 450-micron from the SHARP instrument on the now-decommissioned Caltech Submillimeter Observatory (CSO) and 850-micron data from the POL-2 instrument on the James Clerk Maxwell Telescope (JCMT). Our analysis finds a nearly flat polarization spectrum in the far-infrared, characteristic of a single polarized dust species. We find evidence for a rising polarization spectrum in the high column density molecular gas and a flat spectrum in the low column density HII region. We also use previously published spectral energy distribution parameters of this region to determine possible correlations with polarization spectral shape.

HAWC+/SOFIA Observations of OMC-1: Spectral Energy Distributions

January 06, 2019

Conference proceedings poster, 233st Meeting of the American Astronomical Society, Seattle, Washington

The Orion Molecular Cloud-1, OMC-1, has been well-studied as an example of a region that is actively forming massive stars. The High-resolution Airborne Wideband Camera+, HAWC+, on the SOFIA telescope has observed this region polarimetrically and photometrically at wavelengths of 53, 89, 154, and 214 microns. These new data will help determine the role of magnetic fields in the dynamics of the region. Combining the photometry from HAWC+ with other far-infrared, submillimeter and radio maps, we produce new spectral energy distributions across a ~5-arcminute region from ~50 microns to 3.5 cm. We fit the intensity with a single-temperature modified blackbody and a free-free component that contributes at long wavelengths. We present the resulting maps of temperature, column density and dust emissivity index at 19-arcsecond resolution.

HAWC+/SOFIA Instrumental Polarization Calibration

January 06, 2018

Conference proceedings poster, 231st Meeting of the American Astronomical Society, Washington, D.C.

HAWC+ is a new far-infrared polarimeter for the NASA/DLR SOFIA (Stratospheric Observatory for Infrared Astronomy) telescope. HAWC+ has the capability to measure the polarization of astronomical sources with unprecedented sensitivity and angular resolution in four bands from 50-250 microns. Using data obtained during commissioning flights, we implemented a calibration strategy that separates the astronomical polarization signal from the induced instrumental polarization. The result of this analysis is a map of the instrumental polarization as a function of position in the instrument’s focal plane in each band. The results show consistency between bands, as well as with other methods used to determine preliminary instrumental polarization values.