------------------------------------------------------------------------ chandra_survey.tex ApJ submitted Date: Thu, 26 Jan 2006 14:45:28 -0800 X-Mailer: Apple Mail (2.746.2) X-MailScanner-Information: Please contact postmaster@aoc.nrao.edu for more information X-MailScanner: Found to be clean X-MailScanner-SpamCheck: not spam, SpamAssassin (score=0.001, required 5, autolearn=disabled, HTML_MESSAGE 0.00) X-MailScanner-From: mmuno@astro.ucla.edu --Apple-Mail-7--1052945481 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed %astro-ph/0601627 \documentclass{emulateapj} \usepackage{epsfig} \usepackage{lscape} \newcommand{\etal}{\mbox{et al.}} \newcommand{\ergcms}{erg cm$^{-2}$ s$^{-1}$} \newcommand{\ergs}{erg s$^{-1}$} \newcommand{\phcms}{ph cm$^{-2}$ s$^{-1}$} \newcommand{\degree}{$^\circ$} \newcommand{\msun}{$M_{\odot}$} \newcommand{\pc}{\,{\rm pc}} \newcommand{\yr}{\,{\rm yr}} \newcommand{\gyr}{\,{\rm Gyr}} \newcommand{\emsun}{\,M_\odot} \newcommand{\au}{\,{\rm AU}} \newcommand{\chandra}{{\it Chandra}} \newcommand{\rosat}{{\it ROSAT}} \newcommand{\granat}{{\it GRANAT}} \newcommand{\asca}{{\it ASCA}} \newcommand{\einstein}{{\it Einstein}} \newcommand{\bepposax}{{\it BeppoSAX}} \newcommand{\xmm}{{\it XMM-Newton}} \newcommand{\integral}{{\it INTEGRAL}} \newcommand{\rxte}{{\it RXTE}} \newcommand{\fdeg}{\mbox{$.\!^{\circ}$}} \newcommand{\sgrastar}{\mbox{Sgr A$^*$}} \newcommand{\ebh}{\mbox{1E 1740.7--2942}} \newcommand{\program}[1]{{\tt {#1}}} \makeatletter \newenvironment{inlinefigure}{% \def\@captype{figure}% \noindent\begin{minipage}{0.999\linewidth}\begin{center}} {\end{center}\end{minipage}\smallskip} \newcommand\newtablebreak{\cr\ptable@@split}%\\{\cr\ptable@@split}% \makeatother \shortauthors{Muno \etal} \shorttitle{X-ray Sources in the Nuclear Bulge} %\submitted{} %\received{2002 November 25} \begin{document} \title{A Chandra Catalog of X-ray Sources in the Central 150 pc of the Galaxy} \author{M. P. Muno,\altaffilmark{1,2} F. E. Bauer,\altaffilmark{3,4} R. M. Bandyopadhyay,\altaffilmark{5,6} and Q. D. Wang\altaffilmark{7,8} } California, Los Angeles, CA 90095; mmuno@astro.ucla.edu} \altaffiltext{2}{Hubble Fellow} \altaffiltext{3}{Columbia Astrophysics Laboratory, Columbia University, Pupin Laboratories, 550 W. 120th St., Rm 1418, NY, NY, 10027} \altaffiltext{4}{Chandra Fellow} \altaffiltext{5}{Dept. of Astrophysics, University of Oxford, Keble Road, Oxford OX1 3RH, U.K.} \altaffiltext{6}{Dept. of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL, 32611 USA} \altaffiltext{7}{Department of Astronomy, University of Massachusetts, Amherst, MA 01003; wqd@astro.umass.edu} \altaffiltext{8}{Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540} \begin{abstract} We present the catalog of X-ray sources detected in a shallow \chandra \ survey of the inner 2\degree$\times$0.8\degree\ of the Galaxy, and in two deeper observations of the Radio Arches and Sgr B2. The catalog contains 1352 objects that are highly-absorbed ($N_{\rm H}$$\ga$$4\times10^{22}$ cm$^{-2}$) and are therefore likely to lie near the Galactic center ($D$$\approx$8 kpc), and 549 less-absorbed sources that lie within $\la$6 kc of Earth. Based on the inferred luminosities of the X-ray sources and the expected numbers of various classes of objects, we suggest that the sources with $L_{\rm X} \la 10^{33}$ \ergs\ that comprise $\approx$90\% of the catalog are cataclysmic variables, and that the $\approx$100 brighter objects are accreting neutron stars and black holes, young isolated pulsars, and Wolf-Rayet and O stars in colliding-wind binaries. We find that the spatial distribution of X-ray sources matches that of the old stellar population observed in the infrared, which supports our suggestion that most of the X-ray sources are old cataclysmic variables. However, we find that there is an apparent excess of $\approx$10 bright sources in the Radio Arches region. That region is already known to be the site of recent star formation, so we suggest that the bright sources in this region are young high-mass X-ray binaries, pulsars, or WR/O star binaries. We briefly discuss some astrophysical questions that this catalog can be used to address. \end{abstract} \keywords{catalogs --- Galaxy: center --- X-rays: general} Michael Muno (310) 825 1672 Hubble Fellow University of California, Los Angeles 3904 Physics and Astronomy Bldg. 430 Portola Plaza Box 951547 Los Angeles, CA 90095 --Apple-Mail-7--1052945481 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=ISO-8859-1 %astro-ph/0601627

\documentclass{emulateapj}

\usepackage{epsfig}
\usepackage{lscape}

\newcommand{\etal}{\mbox{et = al.}}
\newcommand{\ergcms}{erg cm$^{-2}$ = s$^{-1}$}
\newcommand{\ergs}{erg = s$^{-1}$}
\newcommand{\phcms}{ph cm$^{-2}$ = s$^{-1}$}
\newcommand{\degree}{$^\circ$}
\newcommand{\= msun}{$M_{\odot}$}
\newcommand{\pc}{\,{\rm = pc}}
\newcommand{\yr}{\,{\rm = yr}}
\newcommand{\gyr}{\,{\rm = Gyr}}
\newcommand{\emsun}{\,M_\odot}
\newcommand{\au}{= \,{\rm AU}}

\newcommand{\chandra}{{\it = Chandra}}
\newcommand{\rosat}{{\it = ROSAT}}
\newcommand{\granat}{{\it = GRANAT}}
\newcommand{\asca}{{\it = ASCA}}
\newcommand{\einstein}{{\it = Einstein}}
\newcommand{\bepposax}{{\it = BeppoSAX}}
\newcommand{\xmm}{{\it = XMM-Newton}}
\newcommand{\integral}{{\it = INTEGRAL}}
\newcommand{\rxte}{{\it RXTE}}

\newcommand{\fdeg}{\mbox{$.\!= ^{\circ}$}}

\newcommand{\sgrastar}{\mbox{= Sgr A$^*$}}
\newcommand{\ebh}{\mbox{1E = 1740.7--2942}}

\newcommand{\program}[1]{{\tt= {#1}}}

\makeatletter
\newe= nvironment{inlinefigure}{%
\def\@captype{figure}%
\noi= ndent\begin{minipage}{0.999\linewidth}\begin{center}}
{\end{cent= er}\end{minipage}\smallskip}

\newcommand\newtablebreak{\cr= \ptable@@split}%\\{\cr\ptable@@split}%
\makeatother
\shortauthors{Muno = \etal}
\shorttitle{X-ray Sources in the Nuclear = Bulge}

%\submitted{}
%\rec= eived{2002 November 25}
\begin{document}

\title{A Chandra Catalog of = X-ray Sources in the Central 150 pc of the Galaxy}
\author{M. = P. Muno,\altaffilmark{1,2}
F. E. Bauer,\altaffilmark{3,4} R. = M. Bandyopadhyay,\altaffilmark{5,6}
and Q. D. = Wang\altaffilmark{7,8}
}

\altaffiltext{1}{Department = of Physics and Astronomy, University of California,
Los = Angeles, CA 90095; mmuno@astro.ucla.edu}
\= altaffiltext{2}{Hubble Fellow}
\altaffiltext{3}{Columbia = Astrophysics Laboratory, Columbia University, = Pupin
Laboratories, 550 W. 120th St., Rm 1418, NY, NY, = 10027}
\altaffiltext{4}{Chandra = Fellow}
\altaffiltext{5}{Dept. of Astrophysics, University of = Oxford, Keble Road,
Oxford OX1 3RH, = U.K.}
\altaffiltext{6}{Dept. of Astronomy, University of = Florida, 211 Bryant
Space Science Center, Gainesville, FL, = 32611=A0 USA}
\altaffiltext{7}{Department of Astronomy, = University of Massachusetts,
=A0 Amherst, MA 01003; wqd@astro.umass.edu}
\al= taffiltext{8}{Institute for Advanced Study, Einstein Drive, Princeton, = NJ
08540}


\begin{abstract}
We= present the catalog of X-ray sources detected in a shallow \chandra\ = survey
of the inner 2\degree$\times$0.8\degree\ of the = Galaxy,
and in two deeper observations of the Radio Arches and = Sgr B2.
The catalog contains 1352 objects that are = highly-absorbed
($N_{\rm H}$$\ga$$4\times10^{22}$ cm$^{-2}$) = and are therefore likely to
lie near the Galactic center = ($D$$\approx$8 kpc), and 549 less-absorbed
sources that lie = within $\la$6 kc of Earth.
Based on the inferred luminosities = of the X-ray sources and the
expected numbers of various = classes of objects, we suggest that the
sources with $L_{\rm = X} \la 10^{33}$ \ergs\ that comprise $\approx$90\%
of the = catalog are cataclysmic
variables, and that the $\approx$100 = brighter objects are
accreting neutron stars and black holes, = young isolated pulsars, and
Wolf-Rayet and O stars in = colliding-wind binaries. We find that the spatial =
distribution of X-ray sources matches that of the old stellar = population
observed in the infrared, which supports our =
suggestion that most of the X-ray sources are old cataclysmic = variables.
However, we find that there is an apparent excess = of $\approx$10 bright
sources in the Radio Arches region. = That region is already known to
be the site of recent star = formation, so we suggest that the bright sources
in this = region are young high-mass X-ray binaries, pulsars, or WR/O star =
binaries. We briefly discuss some astrophysical questions = that this catalog
can be used to = address.
\end{abstract}

\keywords{catalogs --- = Galaxy: center --- X-rays: general}


Michael Muno

(310) 825 1672


Hubble Fellow

University of California, Los Angeles

3904 Physics and Astronomy = Bldg.

430 = Portola Plaza

Box 951547

Los Angeles, CA 90095


 =

= --Apple-Mail-7--1052945481--