A New Era of Submillimeter GRB Afterglow Follow-Ups with the Greenland Telescope

Abstract

A planned rapid submillimeter (submm) Gamma Ray Burst (GRBs) follow-up observations conducted using the Greenland Telescope (GLT) is presented. The GLT is a 12-m submm telescope to be located at the top of the Greenland ice sheet, where the high-altitude and dry weather porvides excellent conditions for observations at submm wavelengths. With its combination of wavelength window and rapid responding system, the GLT will explore new insights on GRBs. Summarizing the current achievements of submm GRB follow-ups, we identify the following three scientific goals regarding GRBs: (1) systematic detection of bright submm emissions originating from reverse shock (RS) in the early afterglow phase, (2) characterization of forward shock and RS emissions by capturing their peak flux and frequencies and performing continuous monitoring, and (3) detections of GRBs as a result of the explosion of first-generation stars result of GRBs at a high redshift through systematic rapid follow ups. The light curves and spectra calculated by available theoretical models clearly show that the GLT could play a crucial role in these studies.

First Detection of Radio Linear Polarization in a Gamma-Ray Burst Afterglow

“…We measured a bright submillimeter afterglow of 53.7 ± 0.9 mJy in the 230 GHz band 1.5 days after GRB, which is the brightest afterglow ever detected in the submillimetre range. At the same epoch, the historic GRB030329 was 49.2 ± 1.1 mJy in the 250 GHz band (Sheth et al 2003), while typical submm-detected afterglows are orders of magnitude fainter (Urata et al 2014(Urata et al , 2015. Thus, GRB 171205A is an ideal object for performing the first radio polarimetry.…”

First-generation science cases for ground-based terahertz telescopes

“…As summarized in Urata et al (2015a), the light curves and spectra calculated by available theoretical models clearly show that the GLT could play a crucial role in these studies. The main workhorse wavelengths are mm and submm bands, where observations can be managed even under the marginal weather conditions for the THz sciences.…”

“…We identify the following three scientific goals for the GRB studies with the GLT: (i) systematic detection of bright submm emissions originating from RS in the early afterglow phase, (ii) characterization of FS and RS emissions by capturing their peak flux and frequency and performing continuous monitoring, and (iii) detections of GRBs as a result of the explosion of first-generation stars at high redshift through systematic rapid follow-ups. As summarized in Urata et al (2015a), the light curves and spectra calculated by available theoretical models clearly show that the GLT could play a crucial role in these studies. The main workhorse wavelengths are mm and submm bands, where observations can be managed even under the marginal weather conditions for the THz sciences.…”

“…In another paper, Urata et al (2015a) discuss a possibility and importance of observing GRB afterglows at submm wave-lengths. Since such a ToO type of observational mode is also worth considering, we also give a summary of their paper in Section 5.2.…”

Reverse Shock Emission in Gamma-Ray Bursts Revisited

“…Based on current observational results, more reliable results could also be achieved by including more broadband or more specialized information instead of just photometric or spectroscopic optical data. For instance, one could use early radio data or (sub)mm data [159,160] to search for reverse shock emission signatures [133,161]; one could identify the reverse shock components and diagnose the structure of the magnetic fields in GRB ejecta via the detection of early time optical polarization [152,153]; one could estimate the magnetization degree of the GRB jets by comprehensive considering of the -ray spectrum [162], the early optical lightcurve type, and special X-ray afterglow features, such as the X-ray plateau due to late magnetic energy injection [73].…”