TY - JOUR
T1 - The First Short GRB Millimeter Afterglow
T2 - The Wide-angled Jet of the Extremely Energetic SGRB 211106A
AU - Laskar, Tanmoy
AU - Escorial, Alicia Rouco
AU - Schroeder, Genevieve
AU - Fong, Wen Fai
AU - Berger, Edo
AU - Veres, Péter
AU - Bhandari, Shivani
AU - Rastinejad, Jillian
AU - Kilpatrick, Charles D.
AU - Tohuvavohu, Aaron
AU - Margutti, Raffaella
AU - Alexander, Kate D.
AU - DeLaunay, James
AU - Kennea, Jamie A.
AU - Nugent, Anya
AU - Paterson, K.
AU - Williams, Peter K.G.
N1 - Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022/8/1
Y1 - 2022/8/1
N2 - We present the discovery of the first millimeter afterglow of a short-duration γ-ray burst (SGRB) and the first confirmed afterglow of an SGRB localized by the GUANO system on Swift. Our Atacama Large Millimeter/Sub-millimeter Array (ALMA) detection of SGRB 211106A establishes an origin in a faint host galaxy detected in Hubble Space Telescope imaging at 0.7 ≲ z ≲ 1.4. From the lack of a detectable optical afterglow, coupled with the bright millimeter counterpart, we infer a high extinction, A V ≳ 2.6 mag along the line of sight, making this one of the most highly dust-extincted SGRBs known to date. The millimeter-band light curve captures the passage of the synchrotron peak from the afterglow forward shock and reveals a jet break at t jet = 29.2 − 4.0 + 4.5 days. For a presumed redshift of z = 1, we infer an opening angle, θ jet = (15.°5 ± 1.°4), and beaming-corrected kinetic energy of log ( E K / erg ) = 51.8 ± 0.3 , making this one of the widest and most energetic SGRB jets known to date. Combining all published millimeter-band upper limits in conjunction with the energetics for a large sample of SGRBs, we find that energetic outflows in high-density environments are more likely to have detectable millimeter counterparts. Concerted afterglow searches with ALMA should yield detection fractions of 24%-40% on timescales of ≳2 days at rates of ≈0.8-1.6 per year, outpacing the historical discovery rate of SGRB centimeter-band afterglows.
AB - We present the discovery of the first millimeter afterglow of a short-duration γ-ray burst (SGRB) and the first confirmed afterglow of an SGRB localized by the GUANO system on Swift. Our Atacama Large Millimeter/Sub-millimeter Array (ALMA) detection of SGRB 211106A establishes an origin in a faint host galaxy detected in Hubble Space Telescope imaging at 0.7 ≲ z ≲ 1.4. From the lack of a detectable optical afterglow, coupled with the bright millimeter counterpart, we infer a high extinction, A V ≳ 2.6 mag along the line of sight, making this one of the most highly dust-extincted SGRBs known to date. The millimeter-band light curve captures the passage of the synchrotron peak from the afterglow forward shock and reveals a jet break at t jet = 29.2 − 4.0 + 4.5 days. For a presumed redshift of z = 1, we infer an opening angle, θ jet = (15.°5 ± 1.°4), and beaming-corrected kinetic energy of log ( E K / erg ) = 51.8 ± 0.3 , making this one of the widest and most energetic SGRB jets known to date. Combining all published millimeter-band upper limits in conjunction with the energetics for a large sample of SGRBs, we find that energetic outflows in high-density environments are more likely to have detectable millimeter counterparts. Concerted afterglow searches with ALMA should yield detection fractions of 24%-40% on timescales of ≳2 days at rates of ≈0.8-1.6 per year, outpacing the historical discovery rate of SGRB centimeter-band afterglows.
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U2 - 10.3847/2041-8213/ac8421
DO - 10.3847/2041-8213/ac8421
M3 - Article
AN - SCOPUS:85136277165
SN - 2041-8205
VL - 935
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 1
M1 - L11
ER -