The H II region-molecular cloud complex W3 - Observations of CO, CS, and HCN

Dickel, H. R.; Dickel, J. R.; Wilson, William J.; Werner, M. W.

doi:10.1086/157919

Cited by 22 publications

(22 citation statements)

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“…The velocity and linewidth of the SO emission are in agreement with those of C 18 O measured by Tieftrunk et al (1995). The nonisotopic CO lines, in contrast, are nonsymmetric, double peaked, and display larger linewidths ranging between ∆V = 9 and 18 km s −1 (Hasegawa et al 1994;Dickel et al 1980). Orion-KL -Following up on the detection of SO emission by Gottlieb et al (1978), the interferometric studies by Plambeck et al (1982) and Wright et al (1996) indicated that SO J K = 2 2 − 1 1 emission is localized to within a 11 × 19 region centered on the IRC2 source, known now as the low-velocity part of the "plateau" feature.…”

Section: G5mentioning

confidence: 94%

Zeeman line splitting measurements sampling dense gas in dark cloud and star-forming cores

Uchida

Fiebig

Güsten

2001

A&A

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Abstract. We present measurements of Zeeman splitting in SO JN = 12 − 11 line emission/absorption arising from dense thermal gas (>10 6 cm −3 ) associated with ten compact H II and star-forming regions. No line-of-sight magnetic field, above an average 1σ limit of 0.57 mG, is detected toward any of these sources. The W3(OH) region, found in a previous study to have a line-of-sight field of 3 mG in its dense gas, is thus unique in this respect. The implication of this study is that the magnetic fields in dense clouds are supercritical in the sense that they are not capable of supporting their host clouds against gravitational collapse. The relatively low average field limit is consistent with those theories predicting the quick onset of and short timescales for ambipolar diffusion. Also presented are (1) Zeeman splitting measurements of the CCS JN = 10 − 01 line probing the 10 4−5 cm −3 gas towards three positions in the Taurus star forming region, giving a 1σ average upper limit of 66 µG, and (2) measurements of Zeeman splitting in the OH 2 Π 3/2 J = 7/2 F = 3 + − 3 − hyperfine line toward the compact H II regions DR-21 and G10.62.

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Section: G5mentioning

confidence: 94%

Zeeman line splitting measurements sampling dense gas in dark cloud and star-forming cores

Uchida

Fiebig

Güsten

2001

A&A

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“…It is generally agreed that W4 (IC 1805), located to the east of W3, was the first of the three large H ii regions to be formed and that its expansion might have recently triggered star formation toward the W3 molecular cloud (Elmegreen & Lada 1977;Dickel et al 1980;Thronson et al 1985;Carpenter et al 2000). The close association of the embedded clusters with adjacent H ii regions also suggests that triggering may have played an important role in the formation of these clusters (Lada & Lada 2003).…”

Section: Star Formation Toward W3 Mainmentioning

confidence: 99%

Deep Near‐Infrared Observations of the W3 Main Star‐forming Region

Ojha

Tamura

Nakajima

et al. 2004

ApJ

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We present a deep JHK s -band imaging survey of the W3 Main star-forming region, using the near-infrared camera SIRIUS mounted on the University of Hawaii 2.2 m telescope. The near-infrared survey covers an area of $24 arcmin 2 with 10 limiting magnitudes of $19.0, 18.1, and 17.3 in the J, H, and K s bands, respectively. We construct JHK color-color and J versus JÀH and K versus HÀK color-magnitude diagrams to identify young stellar objects and estimate their masses. Based on these color-color and color-magnitude diagrams, a rich population of young stellar objects is identified that is associated with the W3 Main region. A large number of previously unreported red sources (HÀK > 2) have also been detected around W3 Main. We argue that these red stars are most probably pre-main-sequence stars with intrinsic color excesses. We find that the slope of the K s -band luminosity function (KLF) of W3 Main is lower than the typical values reported for young embedded clusters. The derived slope of the KLF is the same as that found in 1996 by Megeath and coworkers, from which analysis indicated that the W3 Main region has an age in the range of 0.3-1 Myr. Based on the comparison between models of pre-main-sequence stars and the observed color-magnitude diagram, we find that the stellar population in W3 Main is primarily composed of low-mass pre-main-sequence stars. We also report the detection of isolated young stars with large infrared excesses that are most probably in their earliest evolutionary phases.

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“…Their spatial orientation is such that there is very little overlap along the line of sight among the various components providing information about star formation processes. It is generally agreed that W4 was the Ðrst of the three large H II regions to be formed and that its expansion triggered collapse in at least part of the W3 molecular cloud Lada, & Hewagama Dickel (Dickel 1980 ;Thronson, 1985).…”

Section: Introductionmentioning

confidence: 99%

The Dominion Radio Astrophysical Observatory Galactic Plane Survey Pilot Project: The W3/W4/W5/HB 3 Region

Normandeau

Taylor

Dewdney

1997

ASTROPHYS J SUPPL S

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The Dominion Radio Astrophysical Observatory, in collaboration with other sites, recently began a Galactic plane survey. The data from the pilot project for this survey are presented here. They cover the W3/W4/W5/HB 3 Galactic complex in the Perseus arm. Ten Ðelds were observed to produce mosaic images of this region at two continuum frequencies, 408 and 1420 MHz, as well as in the 21 cm spectral line of atomic hydrogen at 127 velocities covering ]55.5 to [153.9 km s~1. At 1420 MHz (continuum and spectral line), an area of approximately 8¡ ] 6¡ (l ] b) is imaged with a resolution of 1@ .00 ] 1@ .14 (east-west by north-south) whereas, at 408 MHz, the coverage was 14¡ ] 10¡ (l ] b) with a resolution of (east-west by north-south). The spectral-line data cube constitutes the highest resolution atomic 3@ .5 ] 4@ .0 hydrogen study of the entire complex to date. A wealth of large-scale Ðlaments, arcs, bubbles, and shells is revealed.

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The H II region-molecular cloud complex W3 - Observations of CO, CS, and HCN

Cited by 22 publications

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Zeeman line splitting measurements sampling dense gas in dark cloud and star-forming cores

Zeeman line splitting measurements sampling dense gas in dark cloud and star-forming cores

Deep Near‐Infrared Observations of the W3 Main Star‐forming Region

The Dominion Radio Astrophysical Observatory Galactic Plane Survey Pilot Project: The W3/W4/W5/HB 3 Region

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