J/ApJS/69/99 J/ApJS/69/99 NGC 6334 centers of star formation JHK photometry S M Straw A R Hyland P J McGregor Astrophys. J. Suppl. Ser. 69 99 1989 1989ApJS...69...99S Clusters, open Photometry, infrared Supernova remnants HII regions ISM: molecules nebulae: individual (NGC 6334) open clusters and associations: general stars: formation stars: luminosity function, mass function We present near-infrared observations of specific sites of high-mass star formation activity in the giant H II region/molecular cloud complex NGC 6334. The observations consist of high-spatial resolution broad-band imaging, chopping photometry, and moderate-resolution spectra. The imaging observations provide full spatial sampling of the stellar population over a significant area of the cloud to a limit of K=13.5mag and reveal many faint red sources around the sites of recent high-mass star formation. We show that most of these sources are associated with the NGC 6334 molecular cloud and are not Galactic field sources. In the majority of the regions the embedded sources are primarily reddened main-sequence stars of low and intermediate mass though in three of the 11 regions studied there is a high proportion of objects showing H-K excesses which are therefore probably pre main-sequence. We identify the red objects in FIR-I as belonging to a very young compact cluster of ~1pc spatial extent. In FIR-V an unexpectedly large number of bright red sources are detected which have CO absorption at 2.3{mu}m. The probability that these objects are Galactic field sources is very low and if they are giant stars associated with NGC 6334 their implied ages (>10^9^yr) are inconsistent with the many indicators of extreme youth in this region. We propose that they form a hitherto unrecognized population of high-luminosity pre-main-sequence objects. Two objects with similar characteristics are also found in images of an area of the NGC 6334 molecular cloud to the north of FIR-V (SH-1). In FIR-V we also find evidence that the molecular outflow from the already known high-mass protostar has triggered intermediate-mass star formation via interaction with the local interstellar medium. Mass functions have been derived for the embedded stellar aggregates under the assumption that all sources lie on the main sequence unless otherwise indicated. The effect of a population of pre-main-sequence objects on the derived mass function slopes is shown to be small. Embedded aggregates in NGC 6334 have stellar mass distributions similar to those found both in young visible clusters and in other embedded clusters. This suggests that the slope of the mass function is relatively insensitive to conditions in the star formation environment and that the solar neighborhood value applies to star formation regions on scales as small as 1pc and of ages less than 10^7^yr.

NGC 633417 19 57.9-35 57 47

IRS IRS name --- n_IRS Note on photometric results number=1 Asterisks indicate chopping photometry results; all other photometry is derived from the images. --- RAh Right ascension (1950) h RAm Right ascension (1950) min RAs Right ascension (1950) s DE- Declination sign --- DEd Declinaiton (1950) deg DEm Declinaiton (1950) arcmin DEs Declinaiton (1950) arcsec Kmag K magnitude mag l_J-H Limit flag on J-H --- J-H J-H colour index mag l_H-K Limit flag on H-K --- H-K H-K colour index mag l_J-K Limit flag on J-K --- J-K J-K colour index mag K0 Derreddened K magnitude number=2 The derivation of dereddened K magnitudes and stellar masses are described in chap IIIb of the paper. mag LogM Stellar mass number=2 The derivation of dereddened K magnitudes and stellar masses are described in chap IIIb of the paper. [solMass] n_LogM Note on Mass number=3 *: Masses taken from Harvey and Gatley 1983ApJ...269..613H #: Masses derived from dereddening to pre-main-sequence tracks (Fig. 10) instead of ZAMS. --- Rem Remarks number=4 Edge: Source not covered by the J and/or H imaging area Opt: Source visible in the SRC-I plate Fore: Likely foreground source based on its near-infrared colors Ext: Extended source at K Neb: Probable knot in diffuse emission Back: Galactic background source (based on CVF data and/or reddening information) CVF: Spectrum obtained (Fig. 3). Abbreviations for previously reported photometry HG: Harvey and Gatley 1983ApJ...269..613H PF: Persi and Ferrari-Toniolo 1982A&A...112..292P BN: Becklin and Neugebauer 1974, Proc. of the Eighth ESLAB Symp. HII regions and the Galactic center, ed. A.F.M. Moorwood (Neuilly: ESRO), p. 39. BE: Braz and Epchtein 1982A&A...111...91B HW: Harvey and Wilding 1984ApJ...280L..19H --- IRS IRS name --- RAh Right ascension (1950) h RAm Right ascension (1950) min RAs Right ascension (1950) s DE- Declination sign --- DEd Declinaiton (1950) deg DEm Declinaiton (1950) arcmin DEs Declinaiton (1950) arcsec Kmag K magnitude mag Marie-Jose Wagner, Patricia Bauer CDS 1997May02 UNKNOWN UNKNOWN Prepared via OCR at CDS. J_ApJS_69_99.xml