[GO2007b] IR 8k , the SIMBAD biblio

2007A&A...475..281G - Astronomy and Astrophysics, volume 475, 281-300 (2007/11-3)

Herbig-Haro flows in B335.

GALFALK M. and OLOFSSON G.

Abstract (from CDS):

To study the Herbig-Haro flows in the nearby dark globule B335. To find new HH objects and H2 knots, make a proper motion map of the flow activity and investigate physical properties through shock models. We have observed optical (Hα and [SII]) and near-IR (2.12µm H2) deep fields and taken optical spectra using the 2.56m Nordic Optical Telescope, as well as a near-UV deep field (U band) using the 3.58m NTT. In addition we present new SPITZER/IRAC (3.5-8.0µm) and MIPS (24µm) observations. We use previous Hα and 2.12µm H2 observations taken 15 and 9 years earlier to make proper motion maps. We then investigate the shock physics by matching our spectra with planar shock models. We discover five new HH objects (HH119D-H) in the eastern and one (HH119I) in the western lobe of the outflow. From proper motions we find an optically bright, roughly E-W oriented group with high space velocities (200-280km/s) and a near-IR bright, slower group (15-75km/s) moving to the ESE. We also find a system of at least 15 H2 knots in the western lobe. This (WNW) counterflow suggests the possibility of a binary outflow source, giving rise to two outflow axes with slightly different orientations. We find that the E-W flow is symmetrical with evidence for two outbursts. We make the first detection of [OI] λλ 6300/63 in HH119B and Hβ in HH119A and B and find their extinctions to be AV≃1.4 and 4.4, respectively. HH119A is found to expand much faster than expected from linear expansion with distance from the outflow source. Using planar shock models we find shock velocities of ∼60km/s (A) and ∼35km/s (B and C). This agrees with A being of higher excitation than B and C. In our U image we detect three of the HH objects and propose that the emission arise from the [OII]λ3728 line and the blue continuum. New SPITZER/IRAC and MIPS observations show most of the HH objects at 4.5µm and a E-W elongated hour-glass shaped structure at the outflow source. Even at 24µm it is not clear whether most of the light is direct or reflected.

Abstract Copyright:

Journal keyword(s): ISM: jets and outflows - infrared: ISM - ISM: lines and bands - stars: formation - ISM: individual objects: B335 - ISM: individual objects: HH119

VizieR on-line data: <Available at CDS (J/A+A/475/281): images.dat fit/*>

Nomenclature: Figs 1, 2, Table 2: [GO2007b] IR Na (Nos 1-8, 6 missing, 4a-4b, 7a-7c, 8a-8o).

Simbad objects: 26

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