Mon.Not.Roy.Astron.Soc.370:1677-1698,2006 We discuss the panchromatic properties of 99,088 galaxies selected from the
SDSS Data Release 1 spectroscopic sample (a flux-limited sample for 1360
deg^2). ...These galaxies are positionally matched to sources detected by ROSAT,
GALEX, 2MASS, IRAS, GB6, FIRST, NVSS and WENSS. We find strong correlations
between the detection fraction at other wavelengths and optical properties such
as flux, colors, and emission-line strengths. Using GALEX, SDSS, and 2MASS
data, we construct the UV-IR broad-band spectral energy distributions for
various types of galaxies, and find that they form a nearly one-parameter
family. For example, based on SDSS u- and r-band data, supplemented with
redshift, the K-band 2MASS magnitudes can be "predicted" with an rms scatter of
only 0.2 mag. When a dust content estimate determined from SDSS data by
Kauffmann et al. (2003) is also utilized, this scatter decreases to 0.1 mag. We
demonstrate that this dust content is indeed higher for galaxies detected by
IRAS and that it can be used to "predict" measured IRAS 60 micron flux density
within a factor of two using only SDSS data. We also show that the position of
a galaxy in the emission-line-based Baldwin-Phillips-Terlevich diagram is
correlated with the optical light concentration index and u-r color determined
from the SDSS broad-band imaging data, and discuss changes in the morphology of
this diagram induced by requiring detections at other wavelengths. We study the
IR-radio correlation and find evidence that its slope may be different for AGN
and star-forming galaxies and related to the H_alpha/H_beta line strength
ratio.
The Apollo X-Ray Fluorescence Spectrometer Jagoda, N.; Kubierschky, K.; Frank, R. ...
IEEE transactions on nuclear science,
02/1974, Letnik:
21, Številka:
1
Journal Article
Recenzirano
Located in the Science Instrument Module of Apollo 15 and 16, the X-ray Fluorescence Spectrometer measured the X-ray fluorescence induced in the lunar surface by the incident solar flux. The ...fluorescing radiation energy spectra is characteristic of the elemental composition of the lunar surface allowing qualitative and quantitative assessments of the lunar surface. This paper provides a description of the detectors, circuit functions, on-board data processing techniques, in-flight calibration, hardware and flight results of the spectrometer.
The HEAO-B Imaging Proportional Counter is an X-ray imaging instrument designed for use in an orbiting observatory. It measures the spatial location and energy of individual X-ray photons by the ...risetime method and pulse height analysis respectively. The IPC can locate 0.1 to 4keV photons to within 1mm, and provides five bits of energy information. The IPC also includes an in-flight calibration source and a gas control system that maintains the counter gas density constant to an accuracy of 0.25%.
We positionally match the 6 cm GB6, 20 cm FIRST and NVSS, and 92 cm WENSS
radio catalogs and find 16,500 matches in ~3,000 deg2 of sky. Using this
unified radio database, we construct radio ..."color-magnitude-morphology"
diagrams and find that they display a clear structure, rather than a random
scatter. We propose a simple, yet powerful, method for morphological
classification of radio sources based on FIRST and NVSS measurements. For a
subset of matched sources, we find optical identifications using the SDSS Data
Release 1 catalogs, and separate them into quasars and galaxies. Compact radio
sources with flat radio spectra are dominated by quasars, while compact sources
with steep spectra, and resolved radio sources, contain substantial numbers of
both quasars and galaxies.
We discuss the panchromatic properties of 99,088 galaxies selected from the SDSS Data Release 1 spectroscopic sample (a flux-limited sample for 1360 deg^2). These galaxies are positionally matched to ...sources detected by ROSAT, GALEX, 2MASS, IRAS, GB6, FIRST, NVSS and WENSS. We find strong correlations between the detection fraction at other wavelengths and optical properties such as flux, colors, and emission-line strengths. Using GALEX, SDSS, and 2MASS data, we construct the UV-IR broad-band spectral energy distributions for various types of galaxies, and find that they form a nearly one-parameter family. For example, based on SDSS u- and r-band data, supplemented with redshift, the K-band 2MASS magnitudes can be "predicted" with an rms scatter of only 0.2 mag. When a dust content estimate determined from SDSS data by Kauffmann et al. (2003) is also utilized, this scatter decreases to 0.1 mag. We demonstrate that this dust content is indeed higher for galaxies detected by IRAS and that it can be used to "predict" measured IRAS 60 micron flux density within a factor of two using only SDSS data. We also show that the position of a galaxy in the emission-line-based Baldwin-Phillips-Terlevich diagram is correlated with the optical light concentration index and u-r color determined from the SDSS broad-band imaging data, and discuss changes in the morphology of this diagram induced by requiring detections at other wavelengths. We study the IR-radio correlation and find evidence that its slope may be different for AGN and star-forming galaxies and related to the H_alpha/H_beta line strength ratio.
We positionally match the 6 cm GB6, 20 cm FIRST and NVSS, and 92 cm WENSS radio catalogs and find 16,500 matches in ~3,000 deg2 of sky. Using this unified radio database, we construct radio ..."color-magnitude-morphology" diagrams and find that they display a clear structure, rather than a random scatter. We propose a simple, yet powerful, method for morphological classification of radio sources based on FIRST and NVSS measurements. For a subset of matched sources, we find optical identifications using the SDSS Data Release 1 catalogs, and separate them into quasars and galaxies. Compact radio sources with flat radio spectra are dominated by quasars, while compact sources with steep spectra, and resolved radio sources, contain substantial numbers of both quasars and galaxies.
Recent claims by Ivezic et al. (2002) that the distribution of the radio-to-optical flux ratio, R, for quasars is bimodal (the so-called quasar radio dichotomy) were questioned on statistical grounds ...by Cirasuolo et al. (2003). We apply the approach suggested by Cirasuolo et al. to a sample of \~10,000 objects detected by SDSS and FIRST, and find support for the quasar radio dichotomy. The discrepancy between the claims by Cirasuolo et al. and the results presented here is most likely because 1) the ~100 times larger sample based on two homogeneous surveys that is used here allows a direct determination of the R distribution, rather than relying on indirect inferences based on Monte Carlo simulations of several heterogeneous surveys 2) the accurate SDSS colors and redshift information allow robust determination of the K-correction for R, which, if unaccounted for, introduces significant scatter that masks the intrinsic properties of the quasar R distribution.
