We present the results of optical and near-IR spectra and mid-infrared images of the star forming region Gy 2-18, which is associated with IRAS 05439+3035. Within this region, there is a star with strong Ha emission that is illuminating an optical reflection nebula. Optical and near-IR spectra indicate that this star, named IRS 11, is a possible Herbig Be star of spectral type BO-B2, with a strong stellar wind and an infrared excess probably originating in a circumstellar dust disk. The mid-infrared images at 8.7, 9.7, and 12.5 æm show the presence of a second very red source, IRS 9, deeply embedded in the cloud and with a remarkably strong silicate feature in absorption. The estimated bolometric luminosity of 8.6103 Lsolar and the infrared spectral index aIR=1.9 suggest that IRS 9 is a massive protostellar object. These two sources form the core of the young stellar cluster associated with Gy 2-18. The infrared luminosity and spectral index of another member, IRS 13, are estimated to be <=165 Lsolar and <=0.44.
Young Stellar Objects in Gy2-18(IRAS05439+3035)
2002
Abstract
We present the results of optical and near-IR spectra and mid-infrared images of the star forming region Gy 2-18, which is associated with IRAS 05439+3035. Within this region, there is a star with strong Ha emission that is illuminating an optical reflection nebula. Optical and near-IR spectra indicate that this star, named IRS 11, is a possible Herbig Be star of spectral type BO-B2, with a strong stellar wind and an infrared excess probably originating in a circumstellar dust disk. The mid-infrared images at 8.7, 9.7, and 12.5 æm show the presence of a second very red source, IRS 9, deeply embedded in the cloud and with a remarkably strong silicate feature in absorption. The estimated bolometric luminosity of 8.6103 Lsolar and the infrared spectral index aIR=1.9 suggest that IRS 9 is a massive protostellar object. These two sources form the core of the young stellar cluster associated with Gy 2-18. The infrared luminosity and spectral index of another member, IRS 13, are estimated to be <=165 Lsolar and <=0.44.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
