Postrefurbishment mission Hubble Space Telescope images of the core of the Orion Nebula: Proplyds, Herbig-Haro objects, and measurements of a circumstellar disk

Details Postrefurbishment mission Hubble Space Telescope images of the core of the Orion Nebula: Proplyds, Herbig-Haro objects, and measurements of a circumstellar disk Postrefurbishment mission Hubble Space Telescope images of the core of the Orion Nebula: Proplyds, Herbig-Haro objects, and measurements of a circumstellar disk

Nov 1994

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994apj...436..194o&link_type=abstract

Astrophysical Journal, Part 1 (ISSN 0004-367X), vol. 436, no. 1, p. 194-202

Other

200

Dimensional Measurement, Disk Galaxies, Herbig-Haro Objects, Orion Nebula, Stellar Envelopes, H Ii Regions, Hubble Space Telescope, Mathematical Models, Photoionization, Statistical Distributions

Scientific paper

We report on observations of M42 made with the Hubble Space Telescope (HST) immediately after the successful repair and refurbishment mission. Images were made in the strongest optical emission lines of H I, (N II), and (O III) and in a bandpass close to V. In a previous paper, the term proplyd was introduced to describe young stars surrounded by circumstellar material rendered visible by being in an H II region. We confirm the proplyd nature of 17 of 18 objects found earlier with the HST, incorporate 13 previously known sources into the class on the basis of their emission-line appearance, and find 26 additional members not seen previously in other wavelengths. Half of the 110 stars brighter than V = 21 show proplyd structure, which implies that more than half of the stars have circumstellar material since nebular structures are more difficult to detect than stars. The highly variable forms of the proplyds can be explained on the basis of balance of ambient stellar gas pressure and radial pressure arising from the stellar wind and radiation pressure of the dominant stars in the region. Arguments are presented explaining the proplyds as disks or flattened envelopes surrounding young stars, hence they are possible planetary disks. The characteristic mass of ionized material is 2 x 1028 g, which becomes a lower limit to the total mass of the proplyds. A new, coordinate-based, designation scheme for compact sources and stars in the vicinity of M42 is proposed and applied. Evidence is presented that one of the previously known bright Herbig-Haro objects (HH 203) may be the result of a stream of material coming from a proplyd shocking against the neutral lid that covers M42. One object, 183-405, is a proplyd seen only in silhouette against the bright nebular background. It is elliptical, with dimensions 0.9 sec by 1.2 sec and surrounds a pre-main-sequence star of at least 0.2 solar mass. The outer parts of this stellar disk are optically thin and allow column mass densities to be determined. We set a lower limit to this disk to be 0.1-4.4 x 1028 g, dependent on the assumed gas to dust mass ratio.

Affiliated with

Also associated with

No associations

Rating

Postrefurbishment mission Hubble Space Telescope images of the core of the Orion Nebula: Proplyds, Herbig-Haro objects, and measurements of a circumstellar disk does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Postrefurbishment mission Hubble Space Telescope images of the core of the Orion Nebula: Proplyds, Herbig-Haro objects, and measurements of a circumstellar disk, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Postrefurbishment mission Hubble Space Telescope images of the core of the Orion Nebula: Proplyds, Herbig-Haro objects, and measurements of a circumstellar disk will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1022528