Morphology and kinematics of Lynds 1642

Russeil, D.; Juvela, M.; Lehtinen, K.; Mattila, K.; Paatero, Pentti

doi:10.1051/0004-6361:20030884

Cited by 16 publications

(36 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Laureijs et al (1987) showed that the radial density distribution ρ(r) follows the ρ(r) ∝ r −2 profile in the outer parts, and a flatter profile in the inner parts. A similar conclusion was drawn by Liljeström (1991) and Russeil et al (2003) from CO data. However, all these studies treated the cloud as a single unit, although it consists of several components.…”

Section: Introductionsupporting

confidence: 86%

ISO far infrared observations of the high latitude cloud L 1642

Lehtinen¹,

Russeil

Juvela³

et al. 2004

A&A

Self Cite

View full text Add to dashboard Cite

Abstract.We have performed a large-scale mapping of the high-latitude, moderate extinction dark cloud L 1642 with ISO (Infrared Space Observatory) at 200 µm to study the properties of dust, the virial equilibrium condition of the cloud, and their relation to star formation. The cloud consists of three denser regions which are connected by diffuse material. Only one of the regions, the one most massive and with the greatest optical depth, is related to a temperature mimimum. The pre-main sequence binary stars IRAS 04325−1419 and IRAS 04327−1419, probably born within the cloud, are located close to this temperature mimimum coinciding with the column density maximum. The minimum dust temperature is ∼13.8 K. The ratio 2E kin /|E pot | for the star-forming region is about 1.2, and thus it is close to being gravitationally bound. However, the other regions are not gravitationally bound. On a 1 −10 spatial scale the radial density distributions, derived from far-infared optical depth maps, are similar between the star-forming and non star-forming regions. The differences that distinguish the star-forming core appear to be its higher density and lower dust temperature.

show abstract

Section: Introductionsupporting

confidence: 86%

ISO far infrared observations of the high latitude cloud L 1642

Lehtinen¹,

Russeil

Juvela³

et al. 2004

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…comm. ) is notably different than the cloud's CO emission at ≈0-1 km s −1 (Liljestrom 1991;Russeil et al 2003), perhaps due to spectroscopic binarity or unusual kinematics. Our proper motion measurement of (µ α , µ δ ) = (−0.6 ± 1.9, +9.3 ± 2.0) mas/yr is consistent with that of the IRASexcess star EW Eri associated with the cloud (Sandell et al 1987), which has a proper motion of (−5.3 ± 5.6, +7.1 ± 5.5 mas/yr) from UCAC4 (Zacharias et al 2013).…”

Section: Massi J0435145−141446 (M6δ/m7 Vl-g)mentioning

confidence: 77%

The Hawaii Infrared Parallax Program. Ii. Young Ultracool Field Dwarfs* †

Liu

Dupuy

Allers

2016

ApJ

230

320

View full text Add to dashboard Cite

We present a large, uniform analysis of young (≈10-150 Myr) ultracool dwarfs, based on new high-precision infrared (IR) parallaxes for 68 objects. We find that low-gravity (vl-g) late-M and L dwarfs form a continuous sequence in IR color-magnitude diagrams, separate from the field population and from current theoretical models. These vl-g objects also appear distinct from young substellar (brown dwarf and exoplanet) companions, suggesting the two populations may have a different range of physical properties. In contrast, at the L/T transition, young, old, and spectrally peculiar objects all span a relatively narrow range in near-IR absolute magnitudes. At a given spectral type, the IR absolute magnitudes of young objects can be offset from ordinary field dwarfs, with the largest offsets occurring in the Y and J bands for late-M dwarfs (brighter than the field) and mid/late-L dwarfs (fainter than the field). Overall, low-gravity (vl-g) objects have the most uniform photometric behavior while intermediate-gravity (int-g) objects are more diverse, suggesting a third governing parameter beyond spectral type 1 This work is largely based on observations obtained with WIRCam, a joint project of CFHT, Taiwan, Korea, Canada, France, and the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii.2 Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. -2 -and gravity class. We examine the moving group membership for all young ultracool dwarfs with parallaxes, changing the status of 23 objects (including 8 previously identified planetary-mass candidates) and fortifying the status of another 28 objects. We use our resulting age-calibrated sample to establish empirical young isochrones and show a declining frequency of vl-g objects relative to int-g objects with increasing age. Notable individual objects in our sample include high-velocity ( 100 km s −1 ) int-g objects; very red late-L dwarfs with high surface gravities; candidate disk-bearing members of the MBM20 cloud and β Pic moving group; and very young distant interlopers. Finally, we provide a comprehensive summary of the absolute magnitudes and spectral classifications of young ultracool dwarfs, using a combined sample of 102 objects found in the field and as substellar companions to young stars.Subject headings: brown dwarfs -proper motions -parallaxes -solar neighborhood IntroductionObservational studies of brown dwarfs have been inspired by two complementary perspectives. One has been the desire to expand the parameter space of classical stellar astrophysics. Brown dwarfs are t...

show abstract

“…4. The contours of the column density map derived from the 13 CO data of Russeil et al (2003) are drawn in the optical depth map in Fig. 4 (left).…”

Section: Colour Temperature Optical Depth and Spectral Index Mapsmentioning

confidence: 99%

“…See Welsh & Shelton (2009) for a description of the Local Bubble. We adopted the distance of 140 pc similarly to Russeil et al (2003) and Lehtinen et al (2004). A&A 563, A125 (2014) L1642 has been studied using several molecules, see Liljestrom (1991) for a review of the early studies.…”

Section: Introductionmentioning

confidence: 99%

“…Liljestrom (1991) studied L1642 in CO, HCO + and NH 3 and concluded that the cloud is in virial equilibrium and older than 10 6 years. More recently, Russeil et al (2003) studied the morphology and kinematics of L1642 using CO observations obtained with the SEST radio telescope. Their results showed that the cloud consists of a main structure at radial velocity 0.2 km s −1 with higher velocity components forming an incomplete ring around it, suggesting an expanding shell.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Multiwavelength study of the high-latitude cloud L1642: chain of star formation

Malinen

Juvela

Zahorecz

et al. 2014

A&A

Self Cite

View full text Add to dashboard Cite

Context. L1642 is one of the two high galactic latitude (|b| > 30 • ) clouds confirmed to have active star formation. Aims. We examine the properties of this cloud, especially the large-scale structure, dust properties, and compact sources at different stages of star formation.Methods. We present high-resolution far-infrared and submillimetre observations with the Herschel and AKARI satellites and millimetre observations with the AzTEC/ASTE telescope, which we combined with archive data from near-and mid-infrared (2MASS, WISE) to millimetre wavelength observations (Planck).Results. The Herschel observations, combined with other data, show a sequence of objects from a cold clump to young stellar objects (YSOs) at different evolutionary stages. Source B-3 (2MASS J04351455-1414468) appears to be a YSO forming inside the L1642 cloud, instead of a foreground brown dwarf, as previously classified. Herschel data reveal striation in the diffuse dust emission around the cloud L1642. The western region shows striation towards the NE and has a steeper column density gradient on its southern side. The densest central region has a bow-shock like structure showing compression from the west and has a filamentary tail extending towards the east. The differences suggest that these may be spatially distinct structures, aligned only in projection. We derive values of the dust emission cross-section per H nucleon of σ e (250 μm) = 0.5−1.5 × 10 −25 cm 2 /H for different regions of the cloud. Modified black-body fits to the spectral energy distribution of Herschel and Planck data give emissivity spectral index β values 1.8-2.0 for the different regions. The compact sources have lower β values and show an anticorrelation between T and β. Conclusions. Markov chain Monte Carlo calculations demonstrate the strong anticorrelation between β and T errors and the importance of millimetre wavelength Planck data in constraining the estimates. L1642 reveals a more complex structure and sequence of star formation than previously known.

show abstract

Morphology and kinematics of Lynds 1642

Cited by 16 publications

References 19 publications

ISO far infrared observations of the high latitude cloud L 1642

ISO far infrared observations of the high latitude cloud L 1642

The Hawaii Infrared Parallax Program. Ii. Young Ultracool Field Dwarfs* †

Multiwavelength study of the high-latitude cloud L1642: chain of star formation

Contact Info

Product

Resources

About