Related papers: A Deep Multicolor Survey V: The M Dwarf Luminosity…
We study a sample of about 1400 disk M dwarfs that are found in 148 fields observed with the Wide Field Camera 2 (WFC2) on the Hubble Space Telescope and 162 fields observed with pre-repair Planetary Camera 1 (PC1), of which 95 of the WFC2…
By using dark nebulae as opaque outer screens, the luminosity function of white dwarfs and M dwarfs has been studied. High-extinction areas towards the Orion A, Serpens and rho Oph cloud complexes were observed, covering a volume…
We derive the disk I-band luminosity function from the Zheng et al. sample of \~1400 disk M dwarfs observed with the Hubble Space Telescope. We adopt a Galactic-height-dependent color-magnitude relation to account for the metallicity…
We study a sample of 257 Galactic disk M dwarfs (8<M_V<18.5) found in images obtained using HST. These include 192 stars in 22 fields imaged with the repaired WFC2 with mean limiting mag I=23.7 and 65 stars in 162 fields imaged with the…
We analyze the disk M dwarfs found in 31 new fields observed with the Wide Field Camera (WFC2) on the Hubble Space Telescope (HST) together with the sample previously analyzed from 22 WFC2 fields and 162 prerepair Planetary Camera (PC1)…
A sample of white dwarfs is selected from SDSS DR3 imaging data using their reduced proper motions, based on improved proper motions from SDSS plus USNO-B combined data. Numerous SDSS and followup spectra (Kilic et al. 2005) are used to…
We investigate the evolution of the galaxy stellar mass function (SMF) and stellar mass density from redshift z=0.2 to z=1.5 of a $K_{AB}$<22-selected sample with highly reliable photometric redshifts and over an unprecedentedly large area.…
We investigate the form of the local vertical density profile of the stars in the Galactic disk, close to the Galactic plane. We use a homogeneous sample of 34000 ultracool dwarfs M7 to L2.5 that all lie within 350 pc of the plane. We fit a…
Using data from the Sloan Digital Sky Survey Early Data Release and SuperCOSMOS Sky Survey scans of POSS-I plates we identify a sample of 2600 subdwarfs using reduced proper motion methods and strict selection criteria. This forms one of…
We present the results from a spectroscopic study of 1080 nearby active M dwarfs, selected by correlating the 2MASS and ROSAT catalogs. We have derived the spectral types and estimated distances for all of our stars. The spectral types…
Surveys for nearby low-luminosity dwarfs tend to avoid the crowded regions of the Galactic Plane. We have devised near-infrared colour-magnitude and colour-colour selection criteria designed to identify late-type M and early-type L dwarfs…
We report the mid- and far-infrared properties of nearby M dwarfs. Spitzer/MIPS measurements were obtained for a sample of 62 stars at 24 um, with subsamples of 41 and 20 stars observed at 70 um and 160 um respectively. We compare the…
Context. M dwarfs are an ideal laboratory for hunting Earth-like planets, and the study of chromospheric activity is an important part of this task. On the one hand, its short-term activity show high levels of magnetic activity that can…
We present the techniques and early results of our program to measure the luminosity function for White Dwarfs in the SuperCOSMOS Sky Survey. Our survey covers over three quarters of the sky to a mean depth of I~19.2, and finds ~9,500…
Luminosity Functions have been obtained for very faint dwarf galaxies in the cores of four rich clusters of galaxies (Abell 2052, 2107, 2199 and 2666). It is found that the luminosity function of dwarf galaxies rises very steeply in these…
We present a 20-pc, volume-limited sample of M7-L8 dwarfs created through spectroscopic follow-up of sources selected from the Two Micron All Sky Survey (2MASS) Second Incremental Release Point Source Catalog. In this paper, we present…
We present here medium resolution (\lambda /\Delta\lambda\sim1200) H- and K-band spectra of M type dwarf stars covering the wavelength range 1.50 - 1.80 {\mu}m and 1.95 - 2.45 {\mu}m. The sample includes 53 dwarf stars (M0V-M7V) from new…
Redshift surveys like the Sloan Digital Sky Survey (SDSS) have given a very precise measurement of the galaxy luminosity function down to about M_R = -17 (~ M_B = -16). Fainter absolute magnitudes cannot be probed because of the flux limit…
M dwarfs with masses 0.1 <= M/M_sol <= 0.3 are under increasing scrutiny because these fully convective stars pose interesting astrophysical questions regarding their magnetic activity and angular momentum history. They also afford the most…
We investigate the evolution of the galaxy luminosity function from the VIMOS-VLT Deep Survey (VVDS) from the present to z=2 in five (U, B, V, R and I) rest-frame band-passes. We use the first epoch VVDS deep sample of 11,034 spectra…