There are exactly 8192 spectral elements (points) in each spectrum, regularly spaced in terms of frequency. The first point corresponds to spectral frequency 0, while point number 8193 (not included) corresponds to the laser frequency. The 632.8nm laser frequency was doubled, producing an effective laser wavelength of about 316.4nm. Tentatively, it may be assumed that the exact laser wavelength is 316.43nm. The spectra have been normalized so that the bluest stars are approximately level from 480 to 1000nm. The spectra are linear in intensity with zero intensity at tabulated zero. It was not possible to make satisfactory atmospheric extinction corrections throughout all of the atmospheric bands; at places where corrections could not be made, the spectra were set (exactly) to zero. Some of these spectra have been published already (H.L. Johnson, Rev. Mex. Astron. Astrof. 2, 71, 1977); the remainder will be published soon (Rev. Mex. Astron. Astrofis., 4, 3). These published spectral plots contain in graphical form the information needed to evaluate the signal-to-noise ratios of the spectra on this tape. (From Harold L. Johnson, Dec. 13, 1977)
A library of 711 cool star synthetic spectra in the wavelength range 485-540nm is presented. The coverage in the parameter space span in surface gravity from 1.0 to 5.0dex at a step of 0.5dex. The range in effective temperature covers from 4000 to 6000K at a step of 250K plus the spectra for 7000 and 8000K. The global chemical compositions are [M/H]=-1.0, -0.5, 0.0, +0.1, +0.2, +0.3 and +0.5. The adopted value of microturbulent velocity is 2km/s but for two sets of nine spectra each. All the spectra are computed at a resolving power =250,000. For each wavelength point the continuum and line blanketed absolute fluxes per unit frequency are given.
This database contains surface brightness profiles in the optical g, r, i, z bands and near-IR H-band for 286 Virgo cluster galaxies. This morphologically-complete sample spans a huge range in galaxy size, luminosity, surface brightness and stellar populations. These data have been used to study the luminosity and surface brightness distribution of Virgo cluster galaxies, in McDonald et al. (2009MNRAS.394.2022M). We find compelling evidence for bimodal populations in surface brightness, with both early- and late-type galaxies having a dearth of intermediate surface brightness galaxies. Most convincing is our confirmation of the result by Tully and Verheijen that the surface brightness of galaxy disks are strongly bimodal (1997ApJ...484..145T) The near-IR H-band data have been obtained from a variety of telescopes. We downloaded archival images for 31/286 and 84/286 bright galaxies from the 2MASS and GOLDMine online databases, respectively. The remaining 171 galaxies have new observations from the UH 2.2-m (130/286), CFHT (20/286) and UKIRT (21/286) telescopes. These data were all reduced in a homogeneous way, as outlined in our data paper. The optical g, r, i, z data were all obtained from the SDSS archives. Surface brightness profiles were extracted homogeneously from the optical and near-IR data following similar procedures, as outlined in our paper (2011MNRAS.414.2055M) The parametric and non-parametric parameters from bulge-disk decompositions of 285 optical griz and near-IR H-band surface brightness (SB) profiles are given in the bdd_* files in this directory. The profiles are stored in the "prof_g", "prof_r", "prof_i", "prof_z" and "prof_h" subdirectories, one for each color.
We present a set of 180 active galactic nucleus (AGN) candidates based on color selection from the IRAS slow-scan deep observations, with color criteria broadened from the initial Point Source Catalog (Cat. <II/125>) samples so as to include similar objects with redshifts up to z=1 and allowing for two-band detections. Spectroscopic identifications have been obtained for 80 (44%); some additional identifications are secure based on radio detections or optical morphology, although yet unobserved spectroscopically. These spectroscopic identifications include 13 type-1 Seyfert galaxies, 17 type-2 Seyferts, 29 starburst galaxies, 7 LINER systems, and 13 emission-line galaxies so heavily reddened as to remain of ambiguous classification.
We have conducted sensitive (1{sigma}<30uJy) 1.4GHz radio observations with the Australia Telescope Compact Array of a field largely coincident with infrared observations of the Spitzer Wide-Area Extragalactic Survey (SWIRE, 2003PASP..115..897L). The field is centered on the European Large Area ISO Survey S1 region and has a total area of 3.9{deg}. We describe the observations and calibration, source extraction, and cross-matching to infrared sources. Two catalogs are presented: one of the radio components found in the image and another of radio sources with counterparts in the infrared and extracted from the literature. 1366 radio components were grouped into 1276 sources, 1183 of which were matched to infrared sources. We discover 31 radio sources with no infrared counterpart at all, adding to the class of Infrared-Faint Radio Sources.
A set of atmosphere models for cool T-Y brown dwarfs and giant exoplanets. Equilibrium chemistry. Valid temperature range: 200-2000K. Only for solar metallicity.
A set of atmosphere models for cool T-Y brown dwarfs and giant exoplanets. Non equilibrium chemistry (strong). Valid temperature range: 200-2000K. Only for solar metallicity.
A set of atmosphere models for cool T-Y brown dwarfs and giant exoplanets. Non equilibrium chemistry (weak). Valid temperature range: 200-2000K. Only for solar metallicity.
We test state-of-the-art model atmospheres for young very-low-mass stars and brown dwarfs in the infrared, by comparing the predicted synthetic photometry over 1.2-24{mu}m to the observed photometry of M-type spectral templates in star-forming regions. We find that (1) in both early and late young M types, the model atmospheres imply effective temperatures (Teff) several hundred Kelvin lower than predicted by the standard pre-main sequence (PMS) spectral type-Teff conversion scale (based on theoretical evolutionary models). It is only in the mid-M types that the two temperature estimates agree. (2) The Teff discrepancy in the early M types (corresponding to stellar masses >~0.4M_{sun}_ at ages of a few Myr) probably arises from remaining uncertainties in the treatment of atmospheric convection within the atmospheric models, whereas in the late M types it is likely due to an underestimation of dust opacity. (3) The empirical and model-atmosphere J-band bolometric corrections are both roughly flat, and similar to each other, over the M-type Teff range. Thus the model atmospheres yield reasonably accurate bolometric luminosities (Lbol), but lead to underestimations of mass and age relative to evolutionary expectations (especially in the late M types) due to lower Teff. We demonstrate this for a large sample of young Cha I and Taurus sources. (4) The trends in the atmospheric model J-K_s_ colors, and their deviations from the data, are similar at PMS and main sequence ages, suggesting that the model dust opacity errors we postulate here for young ages also apply at field ages.
