Quick search Find article
Quick search
Find article

Chandra Orion Ultradeep Project Census of X-Ray Stars in the BN-KL and OMC-1S Regions

FREE

N. Grosso1, E. D. Feigelson2, K. V. Getman2, L. Townsley2, P. Broos2, E. Flaccomio3, M. J. McCaughrean4,5, G. Micela3, S. Sciortino3, J. Bally6, N. Smith6, A. A. Muench7, G. P. Garmire2 and F. Palla8

Show affiliations


We present a study of the X-ray sources detected in the vicinity of two density peaks in the Orion Molecular Cloud 1 (OMC-1) behind the Orion Nebula Cluster (ONC), as seen in the exceptionally deep (~10 days) exposure of the Chandra Orion Ultradeep Project (COUP). We focus on a 40'' × 50'' region around the Becklin-Neugebauer object and Kleinmann-Low nebula (collectively BN-KL) and a 60'' × 75'' region around OMC-1S, a secondary star-forming peak some 90'' south of BN-KL. A total of 43 and 60 X-ray sources were detected in BN-KL and OMC-1S, respectively, of which one-half and one-third, respectively, were found to be foreground members of the ONC, while the remaining sources are identified as obscured X-ray sources with column densities 22 lesssim log(NH/cm-2) lesssim 24. All but 5 and 18 of these sources have near-infrared stellar counterparts, and 22 of these appear to be young stellar objects (YSOs). X-ray sources are found close to four luminous mid-IR sources, namely, BN, IRc3-i2, IRc2-C, and source n; their X-ray variability and spectral properties are typical of coronal activity in low-mass stars rather than wind emission from massive stars, suggesting that the X-ray emission may be arising from companions. The X-ray light curve of the X-ray source close to BN shows a periodicity of ~8.3 days, and from an X-ray image deconvolution of the region around BN, we conclude that either BN itself or a low-mass companion with a projected separation of simeq200 AU was detected. On the other hand, no emission is seen from the bright radio source I, held by some to be the main source of luminosity in BN-KL. In OMC-1S, Chandra unveils a new subcluster of seven YSOs without infrared counterparts. We compare the hard-band X-ray luminosity functions of obscured X-ray sources in BN-KL and OMC-1S with unobscured X-ray sources in the ONC, and we estimate that the true population of obscured sources in BN-KL and OMC-1S is simeq46 and 57 stars, with 90% confidence intervals of 34-71 and 42-82 stars, respectively.


Subject headings

infrared: stars; open clusters and associations: individual (Orion BN-KL, Orion OMC-1S); stars: flare; stars: pre-main sequence; X-rays: stars


Dates

Issue 2 (2005 October)

Received 2005 February 2, accepted for publication 2005 February 23



  1. Chandra Orion Ultradeep Project Census of X-Ray Stars in the BN-KL and OMC-1S Regions

    N. Grosso et al. 2005 ApJS 160 530

  2. Neumann system, spherical pendulum and magnetic fields

    Pavle Saksida 2002 J. Phys. A: Math. Gen. 35 5237

  3. The effects of a magnetic barrier and a nonmagnetic spacer in tunnel structures

    Ali A Shokri and Alireza Saffarzadeh 2004 J. Phys.: Condens. Matter 16 4455

  4. A new structure of a magnetorheological brake with the waveform boundary of a rotary disk

    Tran Hai Nam and Kyoung Kwan Ahn 2009 Smart Mater. Struct. 18 115029

  5. Multiple scattering approach to I K-edge XANES for iodine-doped PVA films

    T Miki et al 2009 J. Phys.: Conf. Ser. 190 012117

  6. Solvent evaporation and interdiffusion in polymer films

    Mesfin Tsige and Gary S Grest 2005 J. Phys.: Condens. Matter 17 S4119

  7. Conceptual improvements of the KKR method

    N Papanikolaou et al 2002 J. Phys.: Condens. Matter 14 2799

  8. Rapid magnetic hardening by rapid thermal annealing in NdFeB-based nanocomposites

    Kung-Te Chu et al 2005 J. Phys. D: Appl. Phys. 38 4009

  9. Tunable coupling of qubits: Nonadiabatic corrections

    Carsten Hutter et al 2006 Europhys. Lett. 74 1088

  10. Characterisation of a water-oxidizing Co-film by XAFS

    Marcel Risch et al 2009 J. Phys.: Conf. Ser. 190 012167

Users also read

What's this?
This innovative new feature generates a list of articles 'also read' by other users based on them reading the original article. Article abstracts citations and references are all considered and weighted accordingly. We hope that this will help you find relevant papers for your research.

  1. X-Ray Emission from Orion Nebula Cluster Stars with Circumstellar Disks and Jets
  2. The Origin of T Tauri X-Ray Emission: New Insights from the Chandra Orion Ultradeep Project
  3. Membership of the Orion Nebula Population from the Chandra Orion Ultradeep Project
More

View by subject




Export








Please login to access our web services, or create an account if you don't yet have one.

You must have cookies enabled in your web browser to be able to login.

Username
Password

Forgotten your password? Get a new one here.