[vsnet-grb-info 20318] GRB 180205A: SEDM Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22414
SUBJECT: GRB 180205A: SEDM Observations
DATE:    18/02/13 15:30:27 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 180205A (Evans et al.,
GCN 22381) 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., 2017,
 astro-ph/1710.02917).

The SEDM began observing the optical counterpart at 04:44 UTC
(18 minutes after the burst trigger time). We performed 2 x 1350 s
exposures over the wavelength range 3800-10600 A. We see no strong
evidence for emission or absorption features at the quoted redshift of
z=1.409 (Tanvir et al., GCN 22384). The continuum emission is well-fit
by a power law spectrum with index alpha = 0.67 (f_nu ~ nu^-alpha).