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J/ApJ/397/520       IRAS observations in Cr A                   (Wilking+, 1992)

IRAS observations of young stellar objects in the Corona Australis dark cloud WILKING B.A., THOMAS P.G., LADA C.J., MEYER M.R., YOUNG E.T. <Astrophys. J. 397, 520 (1992)> =1992ApJ...397..520W (SIMBAD/NED Reference)
ADC_Keywords: YSOs; Infrared sources; Photometry, infrared Keywords: infrared: stars - ISM: clouds - ISM: individual (Corona Australis Cloud) - stars: pre-main sequence Abstract: We present an analysis of IRAS data for a 57pc2 area of the nearby Corona Australis dark cloud complex. A total of 79 far-infrared sources are detected at 12µm or in at least three IRAS bands. Combining these data with both newly obtained and previously published optical/infrared data, a total of 16 IRAS sources are identified with young stellar objects which are in close proximity to the R Coronae Australis cloud or Rossano Cloud B. Among these objects is a cold, heavily obscured young stellar object, IRAS 32, which radiates only in the 25-100µm bands and is found to be associated with an extended near-infrared nebula. The majority of the remaining 63 IRAS sources in our sample appear to be related to field stars. A total of 24 young stellar objects are now known to be associated with the Cr A cloud and we investigate their collective properties through analysis of their spectral energy distributions. As observed for embedded populations in other dark clouds, the shapes of the spectral energy distributions constitute a nearly continuous sequence from cold, heavily obscured objects (extreme Class I) to T Tauri stars (Class II), with about equal numbers of Class I and Class II sources. There is a hint of a segregation of the shapes of the spectral energy distributions with source luminosity: eight of nine sources with L>1.8L display Class I or flat energy distributions. We conclude that star formation in the Cr A cloud has proceeded in a manner similar to that in the rho Ophiuchi cloud in terms of duration and efficiency. We attribute the relatively low number of young stellar objects in Cr A to its lower mass of both low-density and high-density molecular gas. The luminosity function of the Cr A sources is unique only by the presence of six intermediate-luminosity (∼100L) objects. Either the cloud has formed intermediate-mass stars more efficiently than lower mass objects relative to other dark clouds or several of these objects are interlopers. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1 134 15 *IRAS Sources with S(25)/S(12)>0.8. table2 106 64 *IRAS Sources with S(25)/S(12)<0.8. table3 120 59 Near-infrared photometry of IRAS sources
Note to table1 and table2: IRAS sources positions are: 18h52mn≤RA≤19h20mn, -36deg30"≤DE≤-38deg30" Byte-by-byte Description of file: table1 Byte-by-byte Description of file: table1
Bytes Format Units Label Explanations
1- 2 I2 --- No []? Source number 4- 5 I2 h RAh Right ascension 1950 7- 8 I2 min RAm Right ascension 1950 10- 13 F4.1 s RAs Right ascension 1950 15 A1 --- DE- Declination sign 16- 17 I2 deg DEd Declination 1950 19- 20 I2 arcmin DEm Declination 1950 22- 23 I2 arcsec DEs Declination 1950 25 A1 --- l_S12 [<] Limit flag on S12 26- 31 F6.2 Jy S12 Flux density at 12 mum (1) 32 A1 --- u_S12 Uncertainty flag on S12 34- 37 F4.2 arcmin W12 []? Source size deconvolved with a Gaussian beam of 0.76' (12µm) 38 A1 --- u_W12 Uncertainty flag on W12 39 A1 --- n_W12 [p] p indicates that source size is consistent with point source 41- 46 F6.2 Jy S25 Flux density at 25 mum (1) 47 A1 --- u_S25 Uncertainty flag on S25 49- 52 F4.2 arcmin W25 []? Source size deconvolved with a Gaussian beam of 0.77' (25µm) 53 A1 --- u_W25 Uncertainty flag on W25 54 A1 --- n_W25 [p] p indicates that source size is consistent with point source 56 A1 --- l_S60 [<] Limit flag on S60 57- 62 F6.2 Jy S60 Flux density at 60 mum (1) 63 A1 --- u_S60 Uncertainty flag on S60 65- 68 F4.2 arcmin W60 []? Source size deconvolved with a Gaussian beam of 1.39' (60µm) 69 A1 --- n_W60 [p] p indicates that source size is consistent with point source 71 A1 --- l_S100 [<] Limit flag on S100 72- 77 F6.1 Jy S100 []? Flux density at 100 mum (1) 78 A1 --- u_S100 Uncertainty flag on S100 79 A1 --- n_S100 [c] c indicates source confusion 81- 83 F3.1 arcmin W100 []? Source size deconvolved with a Gaussian beam of 2.96' (100µm) 84 A1 --- u_W100 Uncertainty flag on W100 85 A1 --- n_W100 [p] p indicates that source size is consistent with point source 87- 93 A7 --- Star Visible stars? (2) 95-134 A40 --- Notes Associations, notes (3)
Note (1): Flux densities and source sizes followed by a colon are uncertain due to low signal-to-noise and/or source confusion. "c" indicates source confusion which did not permit a flux determination. All flux densities were determined from in-scan slices using the ADDSCAN utility, except for Sources 21 and 34 which were derived from the Pointed Observations Note (2): "TT" denotes T Tauri star. References to spectral types and Hα emission from Knacke et al. 1973 and Marraco & Rydgren 1981. Note (3): (1) Near-infrared photometry for 2µm sources presented in Table 3 (2) Extended emission associated with visible reflection nebula. (3) Source is badly confused in all bands. Integrated fluxes are greater than 60Jy at 60 mum and greater than 240Jy at 100µm. (4) S CrA is a double with separation of 1.4 (Herbig 1962). (5) Far-infrared source also mapped by Cruz-Gonzales, McBreen, & Fazio 1984 and/or Wilking et al. 1985. (6) TS 13.1, R1, and R2 are from the 2µm survey of Taylor & Storey 1984. (7) The HH100-IR source is confused with R CrA. Flux densities for both sources were derived assuming R CrA is a point source in all bands. (8) VV CrA is a double star with separation of 2" with companion brightest in the infrared (B. Reipurth 1991, private comm.). (9) VSS 10 is from the 2 mum survey of Vrba, Strom, & Strom 1976a. (10) Source associated with Cloud B (Rossano 1978).
Byte-by-byte Description of file: table2
Bytes Format Units Label Explanations
1- 2 I2 --- No []? Source number 4- 5 I2 h RAh Right ascension 1950 7- 8 I2 min RAm Right ascension 1950 10- 13 F4.1 s RAs Right ascension 1950 15 A1 --- DE- Declination sign 16- 17 I2 deg DEd Declination 1950 19- 20 I2 arcmin DEm Declination 1950 22- 23 I2 arcsec DEs Declination 1950 25- 30 F6.2 Jy S12 Flux density at 12 mum (1) 31 A1 --- u_S12 Uncertainty flag on S12 33 A1 --- l_S25 [<] Limit flag on S25 34- 39 F6.2 Jy S25 Flux density at 25 mum (1) 40 A1 --- u_S25 Uncertainty flag on S25 42 A1 --- l_S60 [<] Limit flag on S60 43- 47 F5.2 Jy S60 Flux density at 60 mum (1) 49 A1 --- l_S100 [<] Limit flag on S100 50- 54 F5.2 Jy S100 []? Flux density at 100 mum (1) 55 A1 --- n_S100 [c] c indicates source confusion 57- 64 A8 --- Star Visible stars? (2) 67-106 A40 --- Notes Associations, notes (3)
Note (1): Flux densities and source sizes followed by a colon are uncertain due to low signal-to-noise and/or source confusion. "c" indicates where source confusion did not permit a flux determination. All flux densities were determined from in-scan slices using the ADDSCAN. Upper limits are 3 times the rms noise. Except where noted in col. "Notes", all in-scan sources sizes are consistent with point sources. Note (2): "Yes" denotes star(s) of magnitude 13 or brighter at photographic B or V within 45" in r.a. and 25" in decl. of the IRAS position. Star names are from either the SAO catalog or the Guide Star Catalog. Spectral classifications are given as recorded in the SIMBAD database. Note (3): (1) Also GSC 7421.0894 (2) Cirrus heated by nearbyB8 IV star (Leene 1986). Deconvolved source sizes are W(12)=1.9", W(25)=3.0', W(60)=1.8', and W(100)=4.1". See Leene for integrated fluxes. (3) Mira variable (Feast, 1963) (4) A foreground eclipsing binary star (Tapia & Whelan, 1975). (5) Photometry for 2µm sources associated with IRAS source is presented in table3. (6) Visible star in polarimetric study of Vrba, Strom & Strom 1976b (VSSb) or Vrba, Coyne & Tapia 1984 (VCT). (7) Deconvolved source sizes are W(12)=0.82', W(25)=1.1', and W(60)=1.0'. (8) IRAS LRS spectrum displays 10µm emission feature plus "blue" continuum characteristics of an AGB star (Olnon & Raimond 1986) (9) Also GSC 7917.0901 which appears to be variable. (10) A foreground star which is double (Penny 1979). (11) A foreground star, HR 7232 (12) A foreground star, HR 7254
Byte-by-byte Description of file: table3
Bytes Format Units Label Explanations
1- 10 A10 --- Name Source name 12- 13 I2 h RAh Right ascension 1950 15- 16 I2 min RAm Right ascension 1950 18- 21 F4.1 s RAs Right ascension 1950 23 A1 --- DE- Declination sign 24- 25 I2 deg DEd Declination 1950 27- 28 I2 arcmin DEm Declination 1950 30- 31 I2 arcsec DEs Declination 1950 35- 39 A5 --- Vis Visibility (1) 40 A1 --- l_Jmag [>] limit flag on Jmag 41- 45 F5.2 mag Jmag []? J magnitude (2) 48 A1 --- l_Hmag [>] limit flag on Hmag 49- 53 F5.2 mag Hmag []? H magnitude (2) 57- 60 F4.2 mag e_Hmag []? rms uncertainty on Hmag 63 A1 --- l_Kmag [>] limit flag on Kmag 64- 68 F5.2 mag Kmag []? K magnitude (2) 71- 74 F4.2 mag e_Kmag []? rms uncertainty on Kmag 76 A1 --- l_Lmag [>] limit flag on Lmag 77- 81 F5.2 mag Lmag []? L magnitude (2) 82 A1 --- u_Lmag Uncertainty flag on Lmag 84- 87 A4 --- Obs Type of observations (CTIO or IRTF) 91-120 A30 --- Notes Notes (3)
Note (1): "Yes" denotes either star was visible in focal plane camera (V <14 mag) or has published spectrum as referenced in col. "Notes". TT denotes a T Tauri star. Note (2): Magnitudes at H and K are given in cols. Hmag and Kmag and are followed by their statistical one sigma errors in cols. e_Hmag and e_Kmag respectively, when they exceed absolute uncertainties. L photometry is quoted for a 4" (CTIO) or 6" aperture (IRTF). H and K photometry are quoted for a 6" apertures, except where noted in col. "Notes". Note (3): Source names from Glass & Penston 1975 (GP), Vrba, Strom, & Strom 1976a (VSS), Vrba, Strom, & Strom 1976b (VSSb), Marraco & Rydgren 1981 (Hα), Vrba, Coyne, & Tapia 1984 (VCT), and the Guide Star Catalog (GSC, Laskeret al.1990). d: Magnitude could be slightly underestimated due to faint source in sky annulus. e: Spectral type from Vrba & Rydgren 1984. f: Companion to HD 176386. Magnitudes could be slightly overestimated due to contamination from primary. g: Spectral type from Marraco & Rydgren 1981.
References: Cruz-Gonzales I., McBreen B., & Fazio G.G., 1984,ApJ, 279, 679 Feast M.W., 1963, MNRAS, 125, 367 Glass I.S. & Penston M.V., 1975, MNRAS, 172, 227 (GP) Herbig G.H., 1962, Adv. Astron. Astrophys., 1, 47 Knacke R.F. et al., 1973, ApJ, 179, 847 Lasker B.M. et al., 1990, AJ, 99, 2019 (GSC) Leene A., 1986, A&A, 154, 295 Marraco H.G. & Rydgren A.E., 1981, AJ, 86, 62 Olnon F.M. & Raimond E., 1986, A&AS, 65, 607 Penny A.J., 1979, MNRAS, 187, 829 Rossano G.S., 1978, AJ, 83, 234 Tapia S. & Whelan J., 1975, ApJ, 200, 98 Taylor K.N.R. & Storey J.W.V., 1984, MNRAS, 209, 5P (TS) Vrba F.J., Coyne G.V. & Tapia S., 1984, ApJ, 243, 489 (VCT) Vrba F.J. & Rydgren A.E., 1984, ApJ, 283, 123 Vrba F.J., Strom S.E. & Strom K.M., 1976a, AJ, 81, 317 (VSS) Vrba F.J., Strom S.E. & Strom K.M., 1976b, AJ, 81, 958 (VSSb) Wilking B.A. et al., 1985, ApJ, 293, 165 Historical Notes: Keypunched at CDS
(End) Marie-Jose Wagner, Patricia Bauer [CDS] 08-Mar-1995
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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