[vsnet-grb-info 22737] GRB 190613B: SEDM Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24836
SUBJECT: GRB 190613B: SEDM Observations
DATE:    19/06/15 01:26:59 GMT
FROM:    Virginia Cunningham at U of MD  <vcunning at astro.umd.edu>

V. Cunningham (U of Maryland), J. D. Neill (Caltech), S. B. Cenko

(NASA GSFC), and R. Walters (Caltech) report on behalf of the

SEDM team:

We observed the optical counterpart to GRB 190613B (D'Ai et al. GCN 24807)

with the Spectral Energy Distribution Machine (SEDM) on the 60 inch

telescope at Palomar Observatory. The SEDM is a low resolution (R ~ 100)

integral field unit spectrometer with a multi-band (ugri) rainbow camera
imager

(see Blagorodnova et al. 2018, PASP, 130, 035003, and Rigault et al. 2019,

astro-ph/1902.08526).

The SEDM began observing the optical counterpart at 11:00:28 UTC (11.79

minutes after the burst trigger time). We performed an 1800 s exposure over

the wavelength range 3800-9200 A.  We tentatively identify an absorption

feature at ~ 5385 A that is consistent with the Mg II 2796,2803 doublet at
z =

0.92. However, due to the relatively low significance of the feature and
the

lack of corroborating lines, we cannot confirm this redshift currently.
The

continuum emission is well-fit by a power law spectrum with index alpha =
0.09

(f_nu ~ nu^-alpha).