6 research outputs found
A Public, K-Selected, Optical-to-Near-Infrared Catalog of the Extended Chandra Deep Field South (ECDFS) from the MUltiwavelength Survey by Yale-Chile (MUSYC)
We present a new K-selected, optical-to-near-infrared photometric catalog of
the Extended Chandra Deep Field South (ECDFS), making it publicly available to
the astronomical community. The dataset is founded on publicly available
imaging, supplemented by original zJK imaging data obtained as part of the
MUltiwavelength Survey by Yale-Chile (MUSYC). The final photometric catalog
consists of photometry derived from nine band U-K imaging covering the full
0.5x0.5 sq. deg. of the ECDFS, plus H band data for approximately 80% of the
field. The 5sigma flux limit for point-sources is K = 22.0 (AB). This is also
the nominal completeness and reliability limit of the catalog: the empirical
completeness for 21.75 < K < 22.00 is 85+%. We have verified the quality of the
catalog through both internal consistency checks, and comparisons to other
existing and publicly available catalogs. As well as the photometric catalog,
we also present catalogs of photometric redshifts and restframe photometry
derived from the ten band photometry. We have collected robust spectroscopic
redshift determinations from published sources for 1966 galaxies in the
catalog. Based on these sources, we have achieved a (1sigma) photometric
redshift accuracy of Dz/(1+z) = 0.036, with an outlier fraction of 7.8%. Most
of these outliers are X-ray sources. Finally, we describe and release a utility
for interpolating restframe photometry from observed SEDs, dubbed InterRest.
Particularly in concert with the wealth of already publicly available data in
the ECDFS, this new MUSYC catalog provides an excellent resource for studying
the changing properties of the massive galaxy population at z < 2. (Abridged)Comment: Re-submitted to ApJSS after a first referee report. 27 pages, 17
figures. MUSYC data is freely available from http://astro.yale.edu/MUSYC .
Links to phot-z and restframe photometry catalogs, as well as to InterRest
access and documentation, including a full walkthrough, can be found at
http://www.strw.leidenuniv.nl/~ent
Cygnus X-3 with ISO: investigating the wind
We observed the energetic binary Cygnus X-3 in both quiescent and flaring
states between 4 and 16 microns using the ISO satellite. We find that the
quiescent source shows the thermal free-free spectrum typical of a hot, fast
stellar wind, such as from a massive helium star. The quiescent mass-loss rate
due to a spherically symmetric, non-accelerating wind is found to be in the
range 0.4-2.9 x 10E-4 solar masses per year, consistent with other infrared and
radio observations, but considerably larger than the 10E-5 solar masses per
year deduced from both the orbital change and the X-ray column density. There
is rapid, large amplitude flaring at 4.5 and 11.5 microns at the same time as
enhanced radio and X-ray activity, with the infrared spectrum apparently
becoming flatter in the flaring state. We believe non-thermal processes are
operating, perhaps along with enhanced thermal emission.Comment: Accepted for publication in MNRAS, 11 pages, 6 figure