J/ApJ/758/105 Chandra observations of NGC2903 central regions (Yukita+, 2012)
Hot diffuse emission in the nuclear starburst region of NGC 2903.
Yukita M., Swartz D.A., Tennant A.F., Soria R., Irwin J.A.
<Astrophys. J., 758, 105 (2012)>
=2012ApJ...758..105Y 2012ApJ...758..105Y
ADC_Keywords: X-ray sources ; Galaxies, nearby
Keywords: galaxies: evolution; galaxies: individual: NGC 2903;
galaxies: nuclei; X-rays: galaxies
Abstract:
We present a deep Chandra observation of the central regions of the
late-type barred spiral galaxy NGC 2903. The Chandra data reveal soft
(kTe∼0.2-0.5keV) diffuse emission in the nuclear starburst region
and extending ∼2' (∼5kpc) to the north and west of the nucleus. Much
of this soft hot gas is likely to be from local active star-forming
regions; however, besides the nuclear region, the morphology of hot
gas does not strongly correlate with the bar or other known sites of
active star formation. The central ∼650pc radius starburst zone
exhibits much higher surface brightness diffuse emission than the
surrounding regions and a harder spectral component in addition to a
soft component similar to the surrounding zones. We interpret the hard
component as also being of thermal origin with kTe∼3.6keV and to be
directly associated with a wind fluid produced by supernovae and
massive star winds similar to the hard diffuse emission seen in the
starburst galaxy M82. The inferred terminal velocity for this hard
component, ∼1100km/s, exceeds the local galaxy escape velocity
suggesting a potential outflow into the halo and possibly escape from
the galaxy gravitational potential. Morphologically, the softer
extended emission from nearby regions does not display an obvious
outflow geometry. However, the column density through which the X-rays
are transmitted is lower in the zone to the west of the nucleus
compared to that from the east and the surface brightness is
relatively higher suggesting some of the soft hot gas originates from
above the disk: viewed directly from the western zone but through the
intervening disk of the host galaxy along sight lines from the eastern
zone. There are several point-like sources embedded in the strong
diffuse nuclear emission zone. Their X-ray spectra show them to likely
be compact binaries. None of these detected point sources are
coincident with the mass center of the galaxy and we place an upper
limit luminosity from any point-like nuclear source to be
<2x1038erg/s in the 0.5-8.0keV band, which indicates that NGC 2903
lacks an active galactic nucleus. Heating from the nuclear starburst
and a galactic wind may be responsible for preventing cold gas from
accreting onto the galactic center.
Description:
NGC 2903 was observed with Chandra using the ACIS-S instrument in
imaging mode on 2010 March 7 (ObsID 11260).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 43 92 Properties of X-ray point sources in NGC 2903
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See also:
B/chandra : The Chandra Archive Log (CXC, 1999-2014)
VII/237 : HYPERLEDA. I. Catalog of galaxies (Paturel+, 2003)
J/ApJ/741/49 : ULX candidates in nearby galaxies (Swartz+, 2011)
J/A+A/521/A8 : Star-forming regions in NGC 2903 bar (Popping+, 2010)
J/AJ/139/1066 : X-ray view of NGC 2403 central region (Yukita+, 2010)
J/MNRAS/396/2295 : Stellar cluster dynamical masses in NGC2903 (Hagele+, 2009)
J/AJ/136/2563 : HI Nearby Galaxy Survey, THINGS (Walter+, 2008)
J/AJ/132/1372 : Chandra observation of NGC 6822 (Tennant+, 2006)
J/ApJS/157/59 : Ultraluminous X-ray sources in nearby galaxies (Liu+, 2005)
J/A+A/414/487 : Optically bright AGN in ROSAT-FSC (Veron-Cetty+, 2004)
J/A+A/405/5 : Catalogue of ISM content of normal galaxies (Bettoni+, 2003)
J/MNRAS/317/234 : HJK photometry of 10 barred spirals (Perez-Ramirez+, 2000)
J/A+AS/142/425 : BVRI photometry of 6 galaxies (Drozdovsky+, 2000)
J/A+AS/133/317 : Stellar kinematics in spiral galaxies (Heraudeau+ 1998)
J/ApJS/111/163 : Einstein X-ray survey of galaxies. I. (Burstein+ 1997)
J/ApJS/95/1 : Atlas of Quasar Energy Distributions (Elvis+ 1994)
J/ApJS/80/531 : An X-ray catalog and atlas of galaxies. (Fabbiano+, 1992)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq [1/92] Running sequence number
4- 5 I2 h RAh Hour of right ascension (J2000)
7- 8 I2 min RAm Minute of right ascension (J2000)
10- 13 F4.1 s RAs Second of right ascension (J2000)
15 A1 --- DE- Sign of declination (J2000)
16- 17 I2 deg DEd Degree of declination (J2000)
19- 20 I2 arcmin DEm Arcminute of declination (J2000)
22- 25 F4.1 arcsec DEs Arcsecond of declination (J2000)
27- 32 F6.1 ct Cts [5.3/2848.3] Number of source counts (0.5-8.0keV);
corrected for the finite-aperture model PSF
34- 37 F4.1 --- S/N [2.4/48.4] Signal to noise ratio
39- 43 F5.2 10+31W Lx [0.04/21] Intrinsic luminosity (0.5-8.0keV)
in 1038erg/s (1)
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Note (1): Intrinsic luminosity (0.5-8.0keV) assuming a power-law spectrum of
index Γ=1.95, nH=2.9x1020cm-2.
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Nomenclature note:
Table 3: X-ray sources are in Simbad.
History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 07-Jul-2014