SIMBAD references

2000AJ....120.1426G - Astron. J., 120, 1426-1435 (2000/September-0)

Chandra X-ray observatory study of the Orion nebula cluster and BN/KL region.

GARMIRE G., FEIGELSON E.D., BROOS P., HILLENBRAND L.A., PRAVDO S.H., TOWNSLEY L. and TSUBOI Y.

Abstract (from CDS):

About 1000 X-ray emitting young pre-main-sequence (PMS) stars distributed in mass from ∼0.05 M brown dwarfs to a ∼50 M O star are detected in an image of the Orion Nebula obtained with the Advanced CCD Imaging Spectrometer on board the Chandra X-Ray Observatory. This is the richest field of sources ever obtained in X-ray astronomy. Individual X-ray luminosities in the Orion Nebula cluster range from the sensitivity limit of 2x1028 ergs.s–1 to ∼1032 ergs.s–1. ACIS sources include 85%-90% of V<20 stars, plus a lower but substantial fraction of deeply embedded stars with extinctions as high as AV≃60. The relationships between X-ray and other PMS stellar properties suggest that X-ray luminosity of lower-mass PMS stars depends more on mass, and possibly stellar rotation, than on bolometric luminosity, as widely reported. In a subsample of 17 unabsorbed stars with mass ≃1 M, X-ray luminosities are constant at a high level around Lx≃2x1030 ergs.s–1 for the first ≃2 Myr while descending the convective Hayashi track, but diverge during the 2-10 Myr phase with X-ray emission plummeting in some stars but remaining high in others. This behavior is consistent with the distribution of X-ray luminosities on the zero-age main sequence and with current theories of their rotational history and magnetic dynamos.

The sources in the Becklin-Neugebauer/Kleinman-Low region of massive star formation are discussed in detail. They include both unabsorbed and embedded low-mass members of the Orion Nebula cluster, the luminous infrared Source n, and a class of sources without optical or infrared counterparts that may be new magnetically active embedded PMS stars. Several X-ray sources are also variable radio emitters, an association often seen in magnetically active PMS stars. Faint X-ray emission is seen close to, but apparently not coincident with, the Becklin-Neugebauer object. Its nature is not clear.


Abstract Copyright:

Journal keyword(s): Infrared Radiation - ISM: Individual: Name: Orion Nebula - Stars: Activity - Stars: Pre-Main-Sequence - X-Rays

VizieR on-line data: <Available at CDS (J/AJ/120/1426): table1.dat table2.dat notes.dat>

Nomenclature: Table 1: [GFB2000] ONC NNN (Nos 1-973) = CXOONC JHHMMSS.s+DDMMSS N=973. Table 2: [GFB2000] BN NN (Nos 1-27) = CXOONC JHHMMSS.s+DDMMSS N=27.

Status in Simbad:  could be processed

CDS comments: Infrared source n = LBLS n, source radio D = GMR D

Simbad objects: 20

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2020.02.25-07:17:36

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