New measurements of the 4He abundance in galactic HII

M-R.L. Cioni; S. Cortiglioni; M. Orsini; E. Palazzi; G.G.C. Palumbo; R.L. Sorochenko; A.P. Tsivilev

doi:10.1007/BFb0104760

New measurements of the 4He abundance in galactic HII

M-R.L. Cioni, S. Cortiglioni, M. Orsini, E. Palazzi, G.G.C. Palumbo, R.L. Sorochenko, A.P. Tsivilev

Research output: Contribution to journal › Article › peer-review

Abstract

Preliminary results of the 4He relative abundance determination from Radio Recombination Lines observations at different frequencies in the Orion, Rosette and W3 HII regions are presented. The Orion HII region has been mapped at both 22 GHz and 36 GHz with the same beamwidth (2 arcmin) using the Medicina and Puschino radio telescopes respectively. The RRLs parameters, together with their variation with frequency and with distance were determined by centering the map on the star ϑ 1 OriC. Three positions were observed in the Rosette HII region at 8.3 GHz leading to the first detection in this region of the transition He92α. The derived 4He relative abundance is considerably greater than the ones obtained from previous measurements. The W3 HII region was observed at 36 GHz and the 4He/H value derived was compared with previous measurements performed with higher spatial resolution.

Original language	English
Pages (from-to)	429-432
Journal	Lecture Notes in Physics
Volume	506
DOIs	https://doi.org/10.1007/BFb0104760
Publication status	Published - 1998

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10.1007/BFb0104760

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title = "New measurements of the 4He abundance in galactic HII",

abstract = "Preliminary results of the 4He relative abundance determination from Radio Recombination Lines observations at different frequencies in the Orion, Rosette and W3 HII regions are presented. The Orion HII region has been mapped at both 22 GHz and 36 GHz with the same beamwidth (2 arcmin) using the Medicina and Puschino radio telescopes respectively. The RRLs parameters, together with their variation with frequency and with distance were determined by centering the map on the star ϑ 1 OriC. Three positions were observed in the Rosette HII region at 8.3 GHz leading to the first detection in this region of the transition He92α. The derived 4He relative abundance is considerably greater than the ones obtained from previous measurements. The W3 HII region was observed at 36 GHz and the 4He/H value derived was compared with previous measurements performed with higher spatial resolution.",

author = "M-R.L. Cioni and S. Cortiglioni and M. Orsini and E. Palazzi and G.G.C. Palumbo and R.L. Sorochenko and A.P. Tsivilev",

note = "“The original publication is available at www.springerlink.com”. Copyright Springer. DOI: 10.1007/BFb0104760 [Full text of this article is not available in the UHRA]",

year = "1998",

doi = "10.1007/BFb0104760",

language = "English",

volume = "506",

pages = "429--432",

journal = "Lecture Notes in Physics",

issn = "0075-8450",

publisher = "Springer Nature",

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TY - JOUR

T1 - New measurements of the 4He abundance in galactic HII

AU - Cioni, M-R.L.

AU - Cortiglioni, S.

AU - Orsini, M.

AU - Palazzi, E.

AU - Palumbo, G.G.C.

AU - Sorochenko, R.L.

AU - Tsivilev, A.P.

N1 - “The original publication is available at www.springerlink.com”. Copyright Springer. DOI: 10.1007/BFb0104760 [Full text of this article is not available in the UHRA]

PY - 1998

Y1 - 1998

N2 - Preliminary results of the 4He relative abundance determination from Radio Recombination Lines observations at different frequencies in the Orion, Rosette and W3 HII regions are presented. The Orion HII region has been mapped at both 22 GHz and 36 GHz with the same beamwidth (2 arcmin) using the Medicina and Puschino radio telescopes respectively. The RRLs parameters, together with their variation with frequency and with distance were determined by centering the map on the star ϑ 1 OriC. Three positions were observed in the Rosette HII region at 8.3 GHz leading to the first detection in this region of the transition He92α. The derived 4He relative abundance is considerably greater than the ones obtained from previous measurements. The W3 HII region was observed at 36 GHz and the 4He/H value derived was compared with previous measurements performed with higher spatial resolution.

AB - Preliminary results of the 4He relative abundance determination from Radio Recombination Lines observations at different frequencies in the Orion, Rosette and W3 HII regions are presented. The Orion HII region has been mapped at both 22 GHz and 36 GHz with the same beamwidth (2 arcmin) using the Medicina and Puschino radio telescopes respectively. The RRLs parameters, together with their variation with frequency and with distance were determined by centering the map on the star ϑ 1 OriC. Three positions were observed in the Rosette HII region at 8.3 GHz leading to the first detection in this region of the transition He92α. The derived 4He relative abundance is considerably greater than the ones obtained from previous measurements. The W3 HII region was observed at 36 GHz and the 4He/H value derived was compared with previous measurements performed with higher spatial resolution.

U2 - 10.1007/BFb0104760

DO - 10.1007/BFb0104760

M3 - Article

SN - 0075-8450

VL - 506

SP - 429

EP - 432

JO - Lecture Notes in Physics

JF - Lecture Notes in Physics

ER -

New measurements of the 4He abundance in galactic HII

Abstract

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