Research

Rapid near-infrared IMAger Spectrometer (RIMAS):

RIMAS is a near-infrared imager and spectrometer being built at NASA Goddard Space Flight Center (GSFC) in partnership with the University of Maryland, College Park and Lowell Observatory. When the instrument is completed it will be permanently installed on the 4.3-meter Discovery Channel Telescope. One of RIMAS's primary purposes is to quickly follow-up gamma-ray burst (GRB) afterglows on the ground after triggers from the Swift Observatory in space. RIMAS is well suited for GRB afterglow follow-up because it has two optical arms which allow for simultaneous multiband coverage in both imaging and low- and high-resolution spectroscopy modes.

My primary role with RIMAS is to operate, characterize, and analyze data for the three detectors (two H2RG science detectors and one InSb Spitzer Legacy detector for a slit-viewer camera). I will incorporate the detector characterization into an in situ data reduction pipeline. My secondary role is to produce a data reduction pipeline for RIMAS to produce publication quality data. Additionally, I will help integrate and commission RIMAS both in the lab and on the Discovery Channel Telescope. We expect to commission the instrument at the end of 2016.


Relevant Publications:

  1. H2RG detector characterization for RIMAS and instrument efficiencies (Toy et al. 2016)
  2. Detector driver systems and photometric estimates for RIMAS (Toy et al. 2014)
  3. Cryogenic optical systems for the rapid infrared imager/spectrometer (RIMAS) (Capone et. al. 2014)
  4. The development and analysis of cryogenic optical systems for the rapid infrared imager/spectrometer (Capone et. al. 2013)

Software:


Gamma-ray Bursts (GRBs):

GRBs are some of the most energetic explosions in the universe. GRBs are hypothesized to come from internal collisions of a central engine jet while GRB afterglows are thought to come from external collisions between the jet and the surrounding material around the progenitor. GRB afterglows can be seen in the whole electromagnetic spectrum. These afterglows can be very bright but rapidly fade as a simple-power law. This makes afterglows easy to identify. GRBs can occur at extremely high redshifts. Due to the combination of brightness, simple power-law signature, and ability to be observed at low to high redshifts, GRBs make excellent probes of the high-redshift universe.

I have worked on a particular GRB that occurred nearby (z=0.145). This burst, GRB 130702A, had an associated supernova (SN). It is thought that all long GRBs have an associated SN (there are some exceptions), but most GRBs are too distant to detect the fainter SN bump. Therefore, it is important to study nearby GRB-SNe to try to understand the GRB-SNe that we cannot observe. This burst also has an intermediate GRB energy and is an interesting object to study to see if GRB energy correlates with SNe properties.

I have also worked on a project to identify the host galaxy properties of Damped Lyman-Alpha (DLA) systems associated with GRBs. Due to the exceptionally bright nature of GRB afterglows, DLAs can easily be identified from the backlight of the afterglow. Once the afterglow has faded, we can image the GRB image to study the host galaxy and connect the host galaxy to the identified DLA. We calculated star formation rates for 45 GRB-DLA host counterparts (33 detections, 12 upper limits). This increases the number of detected DLA host counterparts by a factor of three.



Relevant Publications:

  1. Exploring damped Lyman-alpha system host galaxies using gamma-ray bursts (Accepted for publication in ApJ)
  2. Optical and near-infrared observations of SN 2013dx associated with GRB 130702A (Toy et al. 2016)

Press Releases:

  1. Baltimore Sun J1649+2635 Article Jan. 16, 2015
  2. NRAO J1649+2635 Press Release
  3. CMNS J1649+2635 Press Release
  4. Chandra GRB 140903APress Release