{
  "bibcode": "2003GCN..2212....1B",
  "body": "GRB 030329: High-Resolution Spectroscopy of the Host\n\nJ. S. Bloom (CfA/Harvard), N. Morrell (Las Campanas Observatory),\nS. Mohanty (CfA) report:\n\n\"Beginning May 7.01 UT, we observed the position of the optical\ntransient (Peterson & Price, GCN 1985) of GRB 030329 (Vanderspek et\nal., GCN #1997) using the Magellan Inamori Kyocera Echelle (MIKE)\nCamera on the Baade 6.5 m at the Las Campanas Observatory.  The\ndispersion at 7600 Angstrom (Ang) is 0.053 Ang/pixel. The narrow\nemission lines (Martini et al., GCN #2013; Della Ceca et al., GCN\n#2015; Greiner et al. #2020; Caldwell et al., GCN #2053; Eracleous et\nal., GCN #2117), presumably from the host galaxy, are well detected in\neach 1800 sec exposure.  Using a fit to the H-alpha line, we find the\nheliocentric systemic redshift of the host galaxy is:\n\n         z = 0.168541 +/- 0.000004\n\n(statistical error). This is most precise emission line redshift of a\nGRB host galaxy reported to date. This redshift is consistent with the\nhost redshift reported previously (Greiner et al., GCN #2020;\nEracleous et al., GCN #2117; Caldwell et al., GCN #2053).\n\nThe emission lines are resolved in the dispersion direction with a\nFWHM (H-alpha) of 1.44 +/- 0.02 Ang (56.1 km/s). While the core of the\nemission lines can be fit by a Gaussian, extended wings of emission\nand similar velocity substructure within the profiles are apparent. In\nparticular, we identify a faint emission structure that is ~66 km/s to\nthe red of the central core. The host plus OT continuum is discernible\nin each echelle order redward of ~7000 Ang.\n\nIn ~0.4 arcsecond seeing the emission from the host plus OT is still\nunresolved in the spatial direction. The compactness, the relatively\nlow mass implied by the velocity structure of the emission lines, and\nthe faintness of the host (Blake & Bloom; GCN #2011) all continue to\nsupport the notion of the host of GRB 030329 as an intrinsically\nunderluminous galaxy (Eracleous et al., GCN #2117). Despite the low\noverall star formation rate of the host (Caldwell et al., GCN #2053),\ngiven the high equivalent widths of the detected lines, the\nstar-formation rate per unit mass may be appreciable.\"\n\n\nThis message may be cited.",
  "circularId": 2212,
  "createdOn": 1052296054000,
  "email": "jbloom@cfa.harvard.edu",
  "subject": "GRB 030329: High-Resolution Spectroscopy of the Host",
  "submitter": "Josh Bloom at Harvard/CFA  <jbloom@cfa.harvard.edu>",
  "eventId": "GRB 030329"
}