428 research outputs found
Far infrared supplement: Catalog of infrared observations
The development of a new generation of orbital, airborne and ground-based infrared astronomical observatory facilities, including the infrared astronomical satellite (IRAS), the cosmic background explorer (COBE), the NASA Kuiper airborne observatory, and the NASA infrared telescope facility, intensified the need for a comprehensive, machine-readable data base and catalog of current infrared astronomical observations. The Infrared Astronomical Data Base and its principal data product, this catalog, comprise a machine-readable library of infrared (1 micrometer to 1000 micrometers) astronomical observations published in the scientific literature since 1965
Catalog of infrared observations including: Bibliography of infrared astronomy and index of infrared source positions
The Catalog of Infrared Observations and its Far Infrared Supplement summarize all infrared astronomical observations at infrared wavelengths published in the scientific literature between 1965 and 1982. The Catalog includes as appendices the Bibliography of infrared astronomy which keys observations in the Catalog with the original journal references, and the index of infrared source positions which gives source positions for alphabetically listed sources in the Catalog. The Catalog data base contains over 85,000 observations of about 10,000 infrared sources, of which about 2,000 have no known visible counterpart
Far infrared supplement: Catalog of infrared observations
The Far Infrared Supplement: catalog of infrared observations summarizes all infrared astronomical observations at far infrared wavelengths published in the scientific literature between 1965 and 1982. The Supplement list contains 25% of the observations in the full catalog of infrared observations (C10), and essentially eliminates most visible stars from the listings. The Supplement is more compact than the main Catalog (it does not contain the bibliography and position index of the C10), and is intended for easy reference during astronomical observations
Discovery of the Ultra-Bright Type II-L Supernova 2008es
We report the discovery by the Robotic Optical Transient Experiment
(ROTSE-IIIb) telescope of SN 2008es, an overluminous supernova (SN) at z=0.205
with a peak visual magnitude of -22.2. We present multiwavelength follow-up
observations with the Swift satellite and several ground-based optical
telescopes. The ROTSE-IIIb observations constrain the time of explosion to be
23+/-1 rest-frame days before maximum. The linear decay of the optical light
curve, and the combination of a symmetric, broad H\alpha emission line profile
with broad P Cygni H\beta and Na I \lambda5892 profiles, are properties
reminiscent of the bright Type II-L SNe 1979C and 1980K, although SN 2008es is
greater than 10 times more luminous. The host galaxy is undetected in
pre-supernova Sloan Digital Sky Survey images, and similar to Type II-L SN
2005ap (the most luminous SN ever observed), the host is most likely a dwarf
galaxy with M_r > -17. Swift Ultraviolet/Optical Telescope observations in
combination with Palomar photometry measure the SED of the SN from 200 to 800
nm to be a blackbody that cools from a temperature of 14,000 K at the time of
the optical peak to 6400 K 65 days later. The inferred blackbody radius is in
good agreement with the radius expected for the expansion speed measured from
the broad lines (10,000 km/s). The bolometric luminosity at the optical peak is
2.8 x 10^44 erg/s, with a total energy radiated over the next 65 days of 5.6 x
10^50 erg. We favor a model in which the exceptional peak luminosity is a
consequence of the core-collapse explosion of a progenitor star with a low-mass
extended hydrogen envelope and a stellar wind with a density close to the upper
limit on the mass-loss rate measured from the lack of an X-ray detection by the
Swift X-Ray Telescope. (Abridged).Comment: Accepted to ApJ, 14 pages, 7 figures, 3 tables, emulateapj,
corrections from proofs adde
MOSAIC: Software for creating mosaics from collections of images
We have developed a powerful, versatile image processing and analysis software package called MOSAIC, designed specifically for the manipulation of digital astronomical image data obtained with (but not limited to) two-dimensional array detectors. The software package is implemented using the Interactive Data Language (IDL), and incorporates new methods for processing, calibration, analysis, and visualization of astronomical image data, stressing effective methods for the creation of mosaic images from collections of individual exposures, while at the same time preserving the photometric integrity of the original data. Since IDL is available on many computers, the MOSAIC software runs on most UNIX and VAX workstations with the X-Windows or Sun View graphics interface
An ultraviolet–optical flare from the tidal disruption of a helium-rich stellar core
The flare of radiation from the tidal disruption and accretion of a star can be used as a marker for supermassive black holes that otherwise lie dormant and undetected in the centres of distant galaxies. Previous candidate flares have had declining light curves in good agreement with expectations, but with poor constraints on the time of disruption and the type of star disrupted, because the rising emission was not observed. Recently, two ‘relativistic’ candidate tidal disruption events were discovered, each of whose extreme X-ray luminosity and synchrotron radio emission were interpreted as the onset of emission from a relativistic jet. Here we report a luminous ultraviolet–optical flare from the nuclear region of an inactive galaxy at a redshift of 0.1696. The observed continuum is cooler than expected for a simple accreting debris disk, but the well-sampled rise and decay of the light curve follow the predicted mass accretion rate and can be modelled to determine the time of disruption to an accuracy of two days. The black hole has a mass of about two million solar masses, modulo a factor dependent on the mass and radius of the star disrupted. On the basis of the spectroscopic signature of ionized helium from the unbound debris, we determine that the disrupted star was a helium-rich stellar core
High Angular Resolution Mid-infrared Imaging of Young Stars in Orion BN/KL
We present Keck LWS images of the Orion BN/KL star forming region obtained in
the first multi-wavelength study to have 0.3-0.5" resolution from 4.7 to 22
microns. The young stellar objects designated infrared source-n and radio
source-I are believed to dominate the BN/KL region. We have detected extended
emission from a probable accretion disk around source-n but infer a stellar
luminosity on the order of only 2000 Lsun. Although source-I is believed to be
more luminous, we do not detect an infrared counterpart even at the longest
wavelengths. However, we resolve the closeby infrared source, IRc2, into an arc
of knots ~1000 AU long at all wavelengths. Although the physical relation of
source-I to IRc2 remains ambiguous, we suggest these sources mark a high
density core (10^7-10^8 pc^-3 over 1000 AU) within the larger BN/KL star
forming cluster. The high density may be a consequence of the core being young
and heavily embedded. We suggest the energetics of the BN/KL region may be
dominated by this cluster core rather than one or two individual sources.Comment: 13 pages including 3 color figures. Accepted to The Astrophysical
Journal Letters pending slight reduction in length. High resolution figures
(jpeg) may be found at
http://cfa-www.harvard.edu/~lincoln/keck.bnkl.midir.ppr
Can CCM law properly represent all extinction curves?
We present the analysis of a large sample of lines of sight with extinction
curves covering wavelength range from near-infrared (NIR) to ultraviolet (UV).
We derive total to selective extinction ratios based on the Cardelli, Clayton
and Mathis (1989, CCM) law, which is typically used to fit the extinction data
both for diffuse and dense interstellar medium. We conclude that the CCM law is
able to fit most of the extinction curves in our sample. We divide the
remaining lines of sight with peculiar extinction into two groups according to
two main behaviors: a) the optical/IR or/and UV wavelength region cannot be
reproduced by the CCM formula; b) the optical/NIR and UV extinction data are
best fit by the CCM law with different values of R_V. We present examples of
such curves. The study of both types of peculiar cases can help us to learn
about the physical processes that affect dust in the interstellar medium, e.g.,
formation of mantles on the surface of grains, evaporation, growing or
shattering.Comment: 6 pages, 4 figures, in "Light, dust and chemical evolution", Journal
of Physics: Conference Serie
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