The Spitzer c2d survey of large, nearby, interstellar clouds. V. Chamaeleon II observed with Irac

Alicia Porras, Jes K. Joørgensen, Lori E. Allen, Neal J. Evans, Tyler L. Bourke, Juan M. Alcalá, Michael M. Dunham, Geoffrey A. Blake, Nicholas Chapman, Lucas Cieza, Paul M. Harvey, Tracy L. Huard, David W Koerner, Lee G. Mundy, Philip C. Myers, Deborah L. Padgett, Anneila I. Sargent, Karl R. Stapelfeldt, Peter Teuben, Ewine F. Van DishoeckZahed Wahhaj, Kaisa E. Young

Research output: Contribution to journalArticle

31 Scopus citations


We present IRAC (3.6, 4.5, 5.8, and 8.0 μm) observations of the Chamaeleon Il molecular cloud. The observed area covers about 1 deg2 defined by AV > 2. Analysis of the data in the 2005 c2d catalogs reveals a small number of sources (40) with properties similar to those of young stellar or substellar objects (YSOs). The surface density of these YSO candidates is low, and contamination by background galaxies appears to be substantial, especially for sources classified as Class I or flat spectral energy distribution (SED). We discuss this problem in some detail and conclude that very few of the candidate YSOs in early evolutionary stages are actually in the Cha II cloud. Using a refined set of criteria, we define a smaller, but more reliable, set of 24 YSO candidates.

Original languageEnglish (US)
Pages (from-to)493-504
Number of pages12
JournalAstrophysical Journal
Issue number1 I
StatePublished - Feb 10 2007



  • Stars: formation
  • Stars: low-mass, brown dwarfs

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Porras, A., Joørgensen, J. K., Allen, L. E., Evans, N. J., Bourke, T. L., Alcalá, J. M., Dunham, M. M., Blake, G. A., Chapman, N., Cieza, L., Harvey, P. M., Huard, T. L., Koerner, D. W., Mundy, L. G., Myers, P. C., Padgett, D. L., Sargent, A. I., Stapelfeldt, K. R., Teuben, P., ... Young, K. E. (2007). The Spitzer c2d survey of large, nearby, interstellar clouds. V. Chamaeleon II observed with Irac. Astrophysical Journal, 656(1 I), 493-504.