J/ApJ/445/280 J/ApJ/445/280 ROSAT survey of the Orion nebula region M Gagne J -P Caillault J R Stauffer Astrophys. J. 445 280 1995 1995ApJ...445..280G II/171 : Parenago catalogue in the area of the Orion nebula (1954) II/36 : UBV & uvby-beta obs. of Orion OB1 Association (Warren+ 1977) J/ApJ/437/361 : Einstein survey of the Orion nebula region (Gagne+ 1994) Abt et al. 1991 ApJ 367, 155 =1991ApJ...367..155A Andrews 1981 A Photometric atlas of the Orion Nebula (Belfadt: Armagh Obs. Press) Attridge & Herbst 1992 ApJ 398, L61 =1992ApJ...398L..61A Attridge & Herbst 1994, in prep. Brun 1935 Pub. Obs. Lyon, 1, No 12 =1935POLyo...1...12B Cohen & Kuhi 1979 ApJS 41, 743 =1979ApJS...41..743C Duncan 1993 ApJ 406, 172 =1993ApJ...406..172D Edwards et al. 1993 AJ 106, 372 =1993AJ....106..372E General Catalogue of Variable Stars =CDS Catalogue: <II/139> Hartmann et al. 1986 ApJ 309, 275 =1986ApJ...309..275H Herbig & Terndrup 1986 ApJ 307, 609 =1986ApJ...307..609H Jones & Walker 1988 AJ 95, 1755 =1988AJ.....95.1755J Mandel & Herbst 1991 ApJ 383, L75 =1991ApJ...383L..75M McNamara & Huels 1983 A&AS 54, 221 =1983A&AS...54..221M McNamara et al. 1989 AJ 97, 1427 =1989AJ.....97.1427M Parenago 1954 =CDS Catalogue: <II/171> Penston 1973, ApJ 183, 505 =1973ApJ...183..505P Penston et al. 1975, MNRAS 171, 219 =1975MNRAS.171..219P Prosser et al. 1994, ApJ 421, 517 =1994ApJ...421..517P Rydgren & Vrba 1984 AJ 89, 399 =1984AJ.....89..399R Strom 1993 private comm. van Altena et al. 1988 AJ 95, 1744 =1988AJ.....95.1744V Walker 1969 ApJ 155, 447 =1969ApJ...155..447W Walker 1983 ApJ 271, 642 =1983ApJ...271..642W Walker 1990 PASP 102, 726 =1990PASP..102..726W Warren & Hesser 1977 ApJS 34, 115 =CDS Catalogue: <II/36> Nebulae X-ray sources ISM: individual (Orion Nebula) stars: pre-main sequence X-rays: stars We present results from three deep ROSAT high-resolution imager observations of the Orion Nebula star-forming region. The X-ray images contain over 1500 catalogued stars in a roughly 0.8deg^2^ region centered on the Trapezium. In all, 389 distinct X-ray sources have been detected, at least two-thirds of which are associated with a single proper-motion cluster member. X-ray emission is detected from stars of all spectral types, from the massive O- and B-type components of the Trapezium to the coolest, low-mass pre-main-sequence (PMS) stars. In this paper, we focus primarily on X-ray emission from the late-type PMS stars. Of the ~100 late-type cluster members with measured spectral types, approximately three-fourths have been detected; we have derived X-ray luminosity upper limits for the remaining stars. We found coronal X-ray emission turns on around spectral type F6, with the upper envelope of activity increasing with decreasing effective temperature.

ROSAT

NoX X-ray number --- RAh Right ascension J2000 h RAm Right ascension J2000 min RAs Right ascension J2000 s DE- Declination sign --- DEd Declination J2000 deg DEm Declination J2000 arcmin DEs Declination J2000 arcsec Count Corrected ROSAT HRI count rate ct/s e_Count rms uncertainty on Count ct/s Mult * indicates multiple candidate optical counterparts. See table3 --- Par Parenago (1954) optical counterpart candidate designation --- J&W Jones & Walker (1988) optical counterpart candidate designation --- Var Variable optical counterpart candidate designation --- Prob Membership probability --- DRA Offset in right ascension arcsec DDE Offset in declination arcsec NoX X-ray number --- Par1 Parenago designation of the first candidate --- J&W1 Jones & Walker (1988) name of the first candidate --- Prob1 Membership probability of the first candidate --- DRA1 Offset in right ascension of the first candidate arcsec DDE1 Offset in declination of the first candidate arcsec Par2 Parenago designation of the second candidate --- J&W2 Jones & Walker (1988) name of the second candidate --- Prob2 Membership probability of the second candidate --- DRA2 Offset in right ascension of the second candidate arcsec DDE2 Offset in declination of the second candidate arcsec Par3 Parenago designation of the third third candidate --- J&W3 Jones & Walker (1988) name of the third candidate --- Prob3 Membership probability of the third candidate --- DRA3 Offset in right ascension of the third candidate arcsec DDE3 Offset in declination of the first candidate arcsec Name Star name --- NoX X-ray number --- Sp Spectral type --- logTeff Effective temperature K u_logTeff Uncertainty flag on logTeff --- Bmag B magnitude mag Vmag V magnitude mag Icmag Ic (Cousins system) magnitude mag AV Visual extinction number=1 When accurate absorption values are available from published estimates, photometric E(B-V) measurements, or the C_Hbeta_ extinction map of the nebula, they are listed in this column. Otherwise we assume moderate absorption (A_V_~0.25mag) and indicate the value with a ')' in column n_AV mag n_AV ')' when AV=0.25mag number=1 When accurate absorption values are available from published estimates, photometric E(B-V) measurements, or the C_Hbeta_ extinction map of the nebula, they are listed in this column. Otherwise we assume moderate absorption (A_V_~0.25mag) and indicate the value with a ')' in column n_AV --- l_vsini Limit flag on vsini --- vsini Spectroscopic rotation velocity km/s Prot Rotational period d l_logLX Limit flag on logLX --- logLX X-ray luminosity 10-7J l_logLX/Lbol Limit flag on logLX/Lbol --- logLX/Lbol X-ray luminosity versus bolometric luminosity --- u_logLX/Lbol Uncertainty flag on logLX/Lbol --- Note Notes number=2 a: Position and proper-motion membership probability from McNamara et al. (1989) b: Position and proper-motion membership probability from Jones & Walker (1988) c: Position and proper-motion membership probability from van Altena et al. (1988) d: Proper-motion membership probability from McNamara & Huels (1983) e: Spectral type, V and Ic band photometry from Edwards et al. (1993) f: Spectral type from Strom (1993) g: Spectral type, B and V band photometry from Duncan (1993) h: Spectral type from Abt, Wang, & Cardona (1991) i: Spectral type from van Altena et al. (1988) j: Spectral type from the General Catalogue of Variable Stars (Kholopov et al. 1985) k: Spectral type from Walker (1983) l: Spectral type, B or V band photometry from Penston et al. (1975) or Penston (1973) m: Spectral type and V band photometry from Cohen & Kuhi (1979) n: Spectral type from Warren & Hesser (1977) o: Spectral type, B and V band photometry from Walker (1969) p: Spectral type from Parenago (1954) q: V and I_c_ band photometry from Prosser et al. (1994) r: V and I_c_ band photometry from Attridge & Herbst (1992) s: Position or spectral type, V and I_c_ band photometry from Herbig & Terndrup (1986) t: B and V band photometry from Duncan (1993) u: B and V band photometry from McNamara et al. (1989) v: B and V band photometry from van Altena et al. (1988) w: B, V, and I_c_ band photometry from Rydgren & Vrba (1984) x: B and V band photometry from Warren & Hesser (1977) y: I_c_ photographic magnitude from Jones & Walker (1988) z: Position, B and V photographic magnitudes from Andrews (1981) A: V photographic magnitude from Brun (1935) B: Position, B photographic or V photovisual magnitude from Parenago (1954) C: The bolometric luminosity of the late-type secondary cannot be determined D: Rotational period from Attridge & Herbst (1994) E: Rotational period from Attridge & Herbst (1992) F: Rotational period from Mandel & Herbst (1991) G: Rotational period from Walker (1990) H: Spectroscopic rotational velocity from Strom (1993) I: Spectroscopic rotational velocity from Duncan (1993) J: Spectroscopic rotational velocity from Abt et al. (1991) K: Spectroscopic rotational velocity from Walker (1990) L: Spectroscopic rotational velocity from Hartmann et al. (1986) M: One of two candidate optical counterparts. Upper limit corresponds to source flux N: Possible blend. Upper limit corresponds to half of source flux --- table2.texLaTeX version of table2 table3.texLaTeX version of table3 table6.texLaTeX version of table6 Patricia Bauer CDS 1996Aug19Marc Gagne <marc@casa.Colorado.EDU> J_ApJ_445_280.xml