15 research outputs found
Mariner 9 high-resolution albedo mapping of Mars
Large and small scale albedo markings obtained from Mariner 9 photographs and ground based telescope observations are shown on quadrangle charts with a scale of 1:5,000,000. Mercator and stereographic projections at the same scale are presented of the various regions of Mars along with explanatory information about their preparation. Changes in the albedo for the Solis Lacus area were observed and are compared with previous data for the same region. Large scale relief maps covering up to 1.7 million sq miles of the Martian surface are included
Extinction in Star-Forming Disk Galaxies from Inclination-Dependent Composite Spectra
Extinction in galaxies affects their observed properties. In scenarios
describing the distribution of dust and stars in individual disk galaxies, the
amplitude of the extinction can be modulated by the inclination of the
galaxies. In this work we investigate the inclination dependency in composite
spectra of star-forming disk galaxies from the Sloan Digital Sky Survey Data
Release 5. In a volume-limited sample within a redshift range 0.065-0.075 and a
r-band Petrosian absolute magnitude range -19.5 to -22 which exhibits a flat
distribution of inclination, the inclined relative to face-on extinction in the
stellar continuum is found empirically to increase with inclination in the g,
r, and i bands. Within the central 0.5 intrinsic half-light radius of the
galaxies, the g-band relative extinction in the stellar continuum for the
highly-inclined objects (axis ratio b/a = 0.1) is 1.2 mag, agreeing with
previous studies. The extinction curve of the disk galaxies is given in the
restframe wavelengths 3700-8000 angstrom, identified with major optical
emission and absorption lines in diagnostics. The Balmer decrement remains
constant with inclination, suggesting a different kind of dust configuration
and/or reddening mechanism in the HII region from that in the stellar
continuum. One factor is shown to be the presence of spatially non-uniform
interstellar extinction, presumably caused by clumped dust in the vicinity of
the HII region.Comment: To appear in the Astrophysical Journa
Infrared composition of the Large Magellanic Cloud
The evolution of galaxies and the history of star formation in the Universe
are among the most important topics in today's astrophysics. Especially, the
role of small, irregular galaxies in the star-formation history of the Universe
is not yet clear. Using the data from the AKARI IRC survey of the Large
Magellanic Cloud at 3.2, 7, 11, 15, and 24 {\mu}m wavelengths, i.e., at the
mid- and near-infrared, we have constructed a multiwavelength catalog
containing data from a cross-correlation with a number of other databases at
different wavelengths. We present the separation of different classes of stars
in the LMC in color-color, and color-magnitude, diagrams, and analyze their
contribution to the total LMC flux, related to point sources at different
infrared wavelengths
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Integrated Photoelectric Magnitudes And Color Indexes Of Bright Galaxies In The Johnson UBV System
Astronom