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Title: THE PHYSICAL ENVIRONMENT OF THE MASSIVE STAR-FORMING REGION W42

Abstract

We present an analysis of multi-wavelength observations from various data sets and Galactic plane surveys to study the star-formation process in the W42 complex. A bipolar appearance of the W42 complex is evident due to the ionizing feedback from the O5–O6 type star in a medium that is highly inhomogeneous. The Very Large Telescope/NACO adaptive-optics K and L{sup ′} images (resolutions ∼0.″2–0.″1) resolved this ionizing source into multiple point-like sources below ∼5000 AU scale. The position angle ∼15° of the W42 molecular cloud is consistent with the H-band starlight mean polarization angle, which in turn is close to the Galactic magnetic field, suggesting the influence of the Galactic field on the evolution of the W42 molecular cloud. Herschel sub-millimeter data analysis reveals three clumps located along the waist axis of the bipolar nebula, with the peak column densities of ∼(3–5) × 10{sup 22} cm{sup −2} corresponding to visual extinctions of A{sub V} ∼ 32–53.5 mag. The Herschel temperature map traces a temperature gradient in W42, revealing regions of 20 K, 25 K, and 30–36 K. Herschel maps reveal embedded filaments (length ∼1–3 pc) that appear to be radially pointed to the denser clump associated with the O5–O6 star, forming amore » hub-filament system. A total of 512 candidate young stellar objects (YSOs) are identified in the complex, ∼40% of which are present in clusters distributed mainly within the molecular cloud, including the Herschel filaments. Our data sets suggest that the YSO clusters, including the massive stars, are located at the junction of the filaments, similar to those seen in the Rosette Molecular Cloud.« less

Authors:
; ;  [1]; ;  [2];  [3]
  1. Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis Enrique Erro # 1, Tonantzintla, Puebla, C.P. 72840, México (Mexico)
  2. Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005 (India)
  3. Physical Research Laboratory, Navrangpura, Ahmedabad—380 009 (India)
Publication Date:
OSTI Identifier:
22525363
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 811; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CLOUDS; DATA ANALYSIS; DENSITY; FEEDBACK; FILAMENTS; IMAGES; MAGNETIC FIELDS; MILKY WAY; NEBULAE; OPTICS; POLARIZATION; STAR EVOLUTION; STARS; TELESCOPES; TEMPERATURE GRADIENTS

Citation Formats

Dewangan, L. K., Luna, A., Mayya, Y. D., Ojha, D. K., Mallick, K. K., and Anandarao, B. G., E-mail: lokeshd@inaoep.mx. THE PHYSICAL ENVIRONMENT OF THE MASSIVE STAR-FORMING REGION W42. United States: N. p., 2015. Web. doi:10.1088/0004-637X/811/2/79.
Dewangan, L. K., Luna, A., Mayya, Y. D., Ojha, D. K., Mallick, K. K., & Anandarao, B. G., E-mail: lokeshd@inaoep.mx. THE PHYSICAL ENVIRONMENT OF THE MASSIVE STAR-FORMING REGION W42. United States. doi:10.1088/0004-637X/811/2/79.
Dewangan, L. K., Luna, A., Mayya, Y. D., Ojha, D. K., Mallick, K. K., and Anandarao, B. G., E-mail: lokeshd@inaoep.mx. Thu . "THE PHYSICAL ENVIRONMENT OF THE MASSIVE STAR-FORMING REGION W42". United States. doi:10.1088/0004-637X/811/2/79.
@article{osti_22525363,
title = {THE PHYSICAL ENVIRONMENT OF THE MASSIVE STAR-FORMING REGION W42},
author = {Dewangan, L. K. and Luna, A. and Mayya, Y. D. and Ojha, D. K. and Mallick, K. K. and Anandarao, B. G., E-mail: lokeshd@inaoep.mx},
abstractNote = {We present an analysis of multi-wavelength observations from various data sets and Galactic plane surveys to study the star-formation process in the W42 complex. A bipolar appearance of the W42 complex is evident due to the ionizing feedback from the O5–O6 type star in a medium that is highly inhomogeneous. The Very Large Telescope/NACO adaptive-optics K and L{sup ′} images (resolutions ∼0.″2–0.″1) resolved this ionizing source into multiple point-like sources below ∼5000 AU scale. The position angle ∼15° of the W42 molecular cloud is consistent with the H-band starlight mean polarization angle, which in turn is close to the Galactic magnetic field, suggesting the influence of the Galactic field on the evolution of the W42 molecular cloud. Herschel sub-millimeter data analysis reveals three clumps located along the waist axis of the bipolar nebula, with the peak column densities of ∼(3–5) × 10{sup 22} cm{sup −2} corresponding to visual extinctions of A{sub V} ∼ 32–53.5 mag. The Herschel temperature map traces a temperature gradient in W42, revealing regions of 20 K, 25 K, and 30–36 K. Herschel maps reveal embedded filaments (length ∼1–3 pc) that appear to be radially pointed to the denser clump associated with the O5–O6 star, forming a hub-filament system. A total of 512 candidate young stellar objects (YSOs) are identified in the complex, ∼40% of which are present in clusters distributed mainly within the molecular cloud, including the Herschel filaments. Our data sets suggest that the YSO clusters, including the massive stars, are located at the junction of the filaments, similar to those seen in the Rosette Molecular Cloud.},
doi = {10.1088/0004-637X/811/2/79},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 811,
place = {United States},
year = {2015},
month = {10}
}