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Title: THE ZEEMAN EFFECT IN THE 44 GHZ CLASS I METHANOL MASER LINE TOWARD DR21(OH)

Abstract

We report detection of the Zeeman effect in the 44 GHz Class I methanol maser line, toward the star-forming region DR21(OH). In a 219 Jy beam{sup −1} maser centered at an LSR velocity of 0.83 km s{sup −1}, we find a 20- σ detection of zB {sub los} = 53.5 ± 2.7 Hz. If 44 GHz methanol masers are excited at n ∼ 10{sup 7–8} cm{sup −3}, then the B versus n {sup 1/2} relation would imply, from comparison with Zeeman effect detections in the CN(1 − 0) line toward DR21(OH), that magnetic fields traced by 44 GHz methanol masers in DR21(OH) should be ∼10 mG. Combined with our detected zB {sub los} = 53.5 Hz, this would imply that the value of the 44 GHz methanol Zeeman splitting factor z is ∼5 Hz mG{sup −1}. Such small values of z would not be a surprise, as the methanol molecule is non-paramagnetic, like H{sub 2}O. Empirical attempts to determine z , as demonstrated, are important because there currently are no laboratory measurements or theoretically calculated values of z for the 44 GHz CH{sub 3}OH transition. Data from observations of a larger number of sources are needed to make such empiricalmore » determinations robust.« less

Authors:
 [1];  [2]
  1. National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States)
  2. Physics Department, DePaul University, 2219 N. Kenmore Avenue, Byrne Hall 211, Chicago, IL 60614 (United States)
Publication Date:
OSTI Identifier:
22663987
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 834; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BEAMS; CARBON NITRIDES; COMPARATIVE EVALUATIONS; COSMIC RADIATION; DETECTION; GHZ RANGE; MAGNETIC FIELDS; MASERS; METHANOL; MOLECULES; PARAMAGNETISM; POLARIZATION; STARS; VELOCITY; WATER; ZEEMAN EFFECT

Citation Formats

Momjian, E., and Sarma, A. P., E-mail: emomjian@nrao.edu, E-mail: asarma@depaul.edu. THE ZEEMAN EFFECT IN THE 44 GHZ CLASS I METHANOL MASER LINE TOWARD DR21(OH). United States: N. p., 2017. Web. doi:10.3847/1538-4357/834/2/168.
Momjian, E., & Sarma, A. P., E-mail: emomjian@nrao.edu, E-mail: asarma@depaul.edu. THE ZEEMAN EFFECT IN THE 44 GHZ CLASS I METHANOL MASER LINE TOWARD DR21(OH). United States. doi:10.3847/1538-4357/834/2/168.
Momjian, E., and Sarma, A. P., E-mail: emomjian@nrao.edu, E-mail: asarma@depaul.edu. Tue . "THE ZEEMAN EFFECT IN THE 44 GHZ CLASS I METHANOL MASER LINE TOWARD DR21(OH)". United States. doi:10.3847/1538-4357/834/2/168.
@article{osti_22663987,
title = {THE ZEEMAN EFFECT IN THE 44 GHZ CLASS I METHANOL MASER LINE TOWARD DR21(OH)},
author = {Momjian, E. and Sarma, A. P., E-mail: emomjian@nrao.edu, E-mail: asarma@depaul.edu},
abstractNote = {We report detection of the Zeeman effect in the 44 GHz Class I methanol maser line, toward the star-forming region DR21(OH). In a 219 Jy beam{sup −1} maser centered at an LSR velocity of 0.83 km s{sup −1}, we find a 20- σ detection of zB {sub los} = 53.5 ± 2.7 Hz. If 44 GHz methanol masers are excited at n ∼ 10{sup 7–8} cm{sup −3}, then the B versus n {sup 1/2} relation would imply, from comparison with Zeeman effect detections in the CN(1 − 0) line toward DR21(OH), that magnetic fields traced by 44 GHz methanol masers in DR21(OH) should be ∼10 mG. Combined with our detected zB {sub los} = 53.5 Hz, this would imply that the value of the 44 GHz methanol Zeeman splitting factor z is ∼5 Hz mG{sup −1}. Such small values of z would not be a surprise, as the methanol molecule is non-paramagnetic, like H{sub 2}O. Empirical attempts to determine z , as demonstrated, are important because there currently are no laboratory measurements or theoretically calculated values of z for the 44 GHz CH{sub 3}OH transition. Data from observations of a larger number of sources are needed to make such empirical determinations robust.},
doi = {10.3847/1538-4357/834/2/168},
journal = {Astrophysical Journal},
number = 2,
volume = 834,
place = {United States},
year = {Tue Jan 10 00:00:00 EST 2017},
month = {Tue Jan 10 00:00:00 EST 2017}
}