Vertical distances from the Galactic disc.Īs part of our study of young embedded clusters in the third Galactic quadrant (e.g. Star formation ocurring near the ``edges'' of the molecular disc,Įither along the Galacic disc in the far outer Galaxy or at large It is of particular interest to search for and characterise the 1993, 2003).įurthermore, since most gas and dust that exist in the Galaxy areĬonfined to the Galactic disc, and are most abundant toward the inner Near-IR nebulosity, denouncing the presence of one or more YSOs (e.g. Scattering off the walls of these cavities allows photonsįrom embedded young stellar objects (YSO) to escape and be detected as Jets and outflows carve cavities into the surrounding molecular
To the disruptive action of newly born stars ( Matzner & McKee 2000). Embedded clusters emerge from molecular clouds owing Star formation sites are commonly associated with molecular materialīelonging to the parental cloud out of which the young stars form.Īs the young stars evolve, they feed from the available gas andĭissipate it. 1997) and found 346 new embedded star clusters, stellar groups, and candidates. (2003) investigated more than 3000 optical and radio nebulae with 2MASS ( Skrutskie et al. Soares & Bica (2003, 2002) studied four low-mass star clusters in the CMaR1 molecular cloud, three of them related to optical reflection nebulae. (1998) found sources around Herbig AeBe stars, part of them related to reflection nebulae. Subsequently, many infrared star clusters and stellar groups have beenįound during surveys towards directions of optical and radio For a considerable period, these nebulae wereĪmong the best tracers of recent star formation ocurring in a region of In the vicinity of reflection nebulae, different types of objects haveīeen found, many associated with young stars and the process of starįormation (e.g. emission-line stars, Herbig-Haro objects, jets and van den Bergh 1966 Barnard 1927 Hubble 1922 Barnard 1913). Since early years, optical reflection nebulae have attracted muchĪttention by their extended morphology and clearly non-point-likeĪppearance (e.g. Key words: stars: formation - stars: pre-main sequence - ISM:Ĭlouds - infrared: stars - dust, extinction - ISM: individual objects: The extinction A V towards the positions of the optical reflection nebula and of the near-IR nebula was found to be Mass of the molecular gas in this region range from 600
State, with stirred gas and supersonic motions. Molecular gas exhibits large line widths indicative of a very dynamical Near-IR nebula, the molecular cloud contains a dense core where the Molecular cloud is fully covered by our CO( J = 1-0) maps and, traced by this line, extends over a region ofĥ.4' and shape (close to circular) similar to spherical Stellar jets or molecular outflows and into our line-of-sight. Invisible source whose light scatters off a cavity carved by previous Near-IR nebula reveals an embedded, optically and near-IR Single star formation episode with about 1 Myr age. Likely to be coeval and to represent two manifestations of the same
Reflection nebula (ESO 368-8) and a near-infrared nebula locatedĪbout 46'' (1.1 pc) from each other. This star formation region displays an optical Images obtained with VLT/ISAAC, millimetre CO spectra obtained with the SEST telescope, and optical V-band images from the YALO telescope. We report the discovery of a near-infrared nebula,Īnd present a CO map revealing a new dense, dynamic cloud core. The lower ``edge'' of the Galactic disc, and characterise the young YSOs) identified earlier, embedded in a molecular cloud located near Presence of a small young stellar cluster (or aggregate of tens of Region well below the Galactic plane towards the optical reflection We investigate the star formation occurring in a Received 1 September 2009 / Accepted 16 November 2009Īims. Universidade de Lisboa - Faculdade de Ciências, Centroĭe Astronomia e Astrofísica da Universidade de Lisboa, ObservatórioĪstronómico de Lisboa, Tapada da Ajuda, 1349-018 Lisboa, Portugal Young stars and reflection nebulae near the lower ``edge'' of the Galactic molecular disc Astronomical objects: linking to databases.Including author names using non-Roman alphabets.Suggested resources for more tips on language editing in the sciences Punctuation and style concerns regarding equations, figures, tables, and footnotes
0 kommentar(er)
