Low Resolution Imaging Spectrograph Research Articles

The Globular Cluster System of M87

We have begun a program with the Low Resolution Imaging Spectrograph, operating with 30 multi-slits per exposure (Oke et al 1994, Cohen et al 1993) on the ten – meter W. M. Keck telescope located on Mauna Kea, Hawaii to observe the globular cluster systems of the Virgo ellipticals. We expect to learn about the dark matter content of galaxy halos, the formation of these halos and their cluster systems, possibly the formation of the galaxy's themselves, the interaction of the cluster system with the galaxy's gravitational potential (i.e. rotation and spinup), and the homogeneity of chemical evolution in various places. The metallicity of the globular clusters versus the metallicity of the underlying galaxy can also by analyzed. In addition the dynamics (i.e. in practice, the rotation and velocity dispersion) of the halo of the parent galaxy versus the globular cluster system can be determined.

The spectrum of the brown dwarf candidate PC0025+0447

view Abstract Citations (16) References (21) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Spectrum of the Brown Dwarf Candidate PC0025+0447 Mould, Jeremy ; Cohen, Judith ; Oke, J. Beverly ; Reid, Neill Abstract A spectrum of the cool dwarf star PC0025+0447 obtained with the Low Resolution Imaging Spectrograph at the Keck telescope yields an upper limit on the lithium to hydrogen ratio. The limit is temperature dependent and ranges from 5 x 10-10 for an effective temperature of 2500 K to 1 x 10-10 at 1900 K. A definitive spectrum of the star's chromospheric emission is presented, but the prominence of the Balmer series is due to the weak thermal emission of the photosphere, rather than extraordinary activity. PC0025+0447 seems more likely to be a cool main sequence star than a young brown dwarf. Publication: The Astronomical Journal Pub Date: June 1994 DOI: 10.1086/117032 Bibcode: 1994AJ....107.2222M Keywords: Brown Dwarf Stars; Celestial Bodies; Main Sequence Stars; Stellar Evolution; Stellar Spectrophotometry; Charge Coupled Devices; Emission Spectra; Stellar Magnitude; Stellar Spectra; Astronomy; BROWN DWARFS; STARS: INDIVIDUAL: PC0025; 0447 full text sources ADS | data products SIMBAD (1)