Foreground Dust Properties towards the Cluster NGC 7380

Fuente: arXiv
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Autori principali: Singh, Sadhana, Pandey, Jeewan C., Hoang, Thiem, Panwar, Neelam, Medhi, Biman J., Joshi, Vishal, Ganesh, Shashikiran
Natura: Preprint
Pubblicazione: 2024
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author Singh, Sadhana
Pandey, Jeewan C.
Hoang, Thiem
Panwar, Neelam
Medhi, Biman J.
Joshi, Vishal
Ganesh, Shashikiran
author_facet Singh, Sadhana
Pandey, Jeewan C.
Hoang, Thiem
Panwar, Neelam
Medhi, Biman J.
Joshi, Vishal
Ganesh, Shashikiran
contents Using starlight polarization, we present the properties of foreground dust towards cluster NGC 7380 embedded in H{\sc ii} region Sh 2-142. Observations of starlight polarization are carried out in four filters using an imaging polarimeter equipped with a 104-cm ARIES telescope. Polarization vectors of stars are aligned along the Galactic magnetic field. Towards the east and southeast regions, the dust structure appears much denser than in other regions (inferred from extinction contours and colour composite image) and is also reflected in polarization distribution. We find that the polarization degree and extinction tend to increase with distance and indication for the presence of a dust layer at a distance of around 1.2 $kpc$. We have identified eight potential candidates exhibiting intrinsic polarization by employing three distinct criteria to distinguish between stars of intrinsic polarization and interstellar polarized stars. For interstellar polarized stars, we find that the maximum polarization degree increases with the color excess and has a strong scatter, with the mean value of 1.71$\pm$0.57$\%$. The peak wavelength spans $0.40-0.88μ$m with the mean value of 0.56$\pm$0.07 $μm$, suggesting similar grain sizes in the region as the average diffuse interstellar medium. The polarization efficiency is also found to decrease with visual extinction as $P_{max}/A_{V}\propto A_{V}^{-0.61}$. Our observational results are found to be consistent with the predictions by the radiative torque alignment theory.
format Preprint
id arxiv_https___arxiv_org_abs_2403_20043
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Foreground Dust Properties towards the Cluster NGC 7380
Singh, Sadhana
Pandey, Jeewan C.
Hoang, Thiem
Panwar, Neelam
Medhi, Biman J.
Joshi, Vishal
Ganesh, Shashikiran
Astrophysics of Galaxies
Solar and Stellar Astrophysics
Using starlight polarization, we present the properties of foreground dust towards cluster NGC 7380 embedded in H{\sc ii} region Sh 2-142. Observations of starlight polarization are carried out in four filters using an imaging polarimeter equipped with a 104-cm ARIES telescope. Polarization vectors of stars are aligned along the Galactic magnetic field. Towards the east and southeast regions, the dust structure appears much denser than in other regions (inferred from extinction contours and colour composite image) and is also reflected in polarization distribution. We find that the polarization degree and extinction tend to increase with distance and indication for the presence of a dust layer at a distance of around 1.2 $kpc$. We have identified eight potential candidates exhibiting intrinsic polarization by employing three distinct criteria to distinguish between stars of intrinsic polarization and interstellar polarized stars. For interstellar polarized stars, we find that the maximum polarization degree increases with the color excess and has a strong scatter, with the mean value of 1.71$\pm$0.57$\%$. The peak wavelength spans $0.40-0.88μ$m with the mean value of 0.56$\pm$0.07 $μm$, suggesting similar grain sizes in the region as the average diffuse interstellar medium. The polarization efficiency is also found to decrease with visual extinction as $P_{max}/A_{V}\propto A_{V}^{-0.61}$. Our observational results are found to be consistent with the predictions by the radiative torque alignment theory.
title Foreground Dust Properties towards the Cluster NGC 7380
topic Astrophysics of Galaxies
Solar and Stellar Astrophysics
url https://arxiv.org/abs/2403.20043