J/A+A/384/890 BVRIHalpha photometry of NGC 2244 X-ray stars (Berghoefer+, 2002)
Optical properties of X-ray selected stars in NGC 2244 in the Rosette Nebula.
Berghoefer T.W., Christian D.J.
<Astron. Astrophys. 384, 890 (2002)>
=2002A&A...384..890B 2002A&A...384..890B
ADC_Keywords: Clusters, open ; X-ray sources ; Photometry, UBVRI
Keywords: galaxy - open clusters and associations: individual: NGC 2244 -
stars: early-type - stars: late-type - stars: activity -
stars: pre-main sequence - X-ray: stars
Abstract:
We present high spatial resolution optical photometry of NGC 2244 in
the Rosette Nebula using the NOAO MOSAIC Imager at Kitt Peak. We
obtained BVIR and Hα images of the central cluster and
surrounding nebulae, and present results for 138 sources selected from
X-ray observations with the ROSAT PSPC and HRI. Color-magnitude
diagrams of the cluster show a large number of the stars are still
undergoing contraction onto the main sequence. The faintest X-ray
selected cluster members have the highest X-ray-to-optical
luminosities (Lx~>7x1030erg/s; Lx/Lbol≃10-2 to 10-3) and
indicate they are a population of young active late-type stars.
Hα emission from the X-ray emitters is also remarkable. We have
extended the detections of PMS stars in NGC 2244 well into the ran ge
of K spectral types. While most of the cluster stars are located in
the color-magnitude diagrams in between the ZAMS and the 3Myrs
isochrone, significantly younger low mass stars exist and confirm
earlier reports that star formation is still going on in the Rosette
Nebula/NGC 2244 region.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 146 138 Summary of optical and X-ray properties of stars
detected in the ROSAT PSPC and HRI observations
of the Rosette Nebula
table3.tex 224 246 LaTeX version of table 3
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See also:
IX/30 : Second ROSAT PSPC Catalog (ROSAT, 2000)
IX/28 : ROSAT HRI Pointed Observations (1RXH) (ROSAT Team, 2000)
Table 1: ROSAT observation log.
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ROR Detector Date Exposure(s)
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WG200196P PSPC Apr. 2, 1992 4300
Oct. 5, 1993 12850
WG202155H HRI Apr. 5-11, 1996 18800
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Running number
5- 6 I2 h RAh Right ascension (J2000)
8- 9 I2 min RAm Right ascension (J2000)
11- 14 F4.1 s RAs Right ascension (J2000)
16 A1 --- DE- Declination sign
17- 18 I2 deg DEd Declination (J2000)
20- 21 I2 arcmin DEm Declination (J2000)
23- 26 F4.1 arcsec DEs Declination (J2000)
28- 32 F5.1 arcsec dRA ? Angular sep. of PSPC and Optical pos. in RA
34- 38 F5.1 arcsec dDE ? Angular sep. of PSPC and Optical pos. in DE
40- 44 F5.2 ct/ks CRpspc PSPC count rate
46- 49 F4.2 ct/ks e_CRpspc Error in PSPC count rate
51- 55 F5.2 [10-7W] logLpspc log of PSPC luminosity
57- 60 F4.2 [10-7W] e_logLpspc Error in PSPC luminosity
62- 66 F5.2 ct/ks CRhri HRI count rate (1)
68- 71 F4.2 ct/ks e_CRhri Error HRI count rate (1)
73- 77 F5.2 [10-7W] logLhri log of HRI luminosity
79- 82 F4.2 [10-7W] e_logLhri Error in logLhri
84- 88 F5.2 mag Bmag ? MOSAIC B magnitude
90- 94 F5.2 mag Vmag ? MOSAIC V magnitude
96-100 F5.2 mag Rmag ? MOSAIC R magnitude
102-106 F5.2 mag Imag ? MOSAIC I magnitude
108-112 F5.2 mag Hamag ? MOSAIC Hα magnitude
114-146 A33 --- Rem Remarks
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Note (1): Errors of 0.00 indicate a 3σ upper limit for HRI count rate
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Acknowledgements: Thomas Berghoefer
(End) Patricia Bauer [CDS] 15-Mar-2002