Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.12386/26476
Title: | Deriving the Extinction to Young Stellar Objects using [Fe II] Near-infrared Emission Lines: Prescriptions from GIANO High-resolution Spectra | Authors: | Pecchioli, T. SANNA, Nicoletta MASSI, Fabrizio OLIVA, Ernesto |
Issue Date: | 2016 | Journal: | PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC | Number: | 128 | Issue: | 965 | First Page: | 073001 | Abstract: | The near-infrared (NIR) emission lines of Fe<SUP>+</SUP> at 1.257, 1.321, and 1.644 μm share the same upper level; their ratios can then be exploited to derive the extinction to a line emitting region once the relevant spontaneous emission coefficients are known. This is commonly done, normally from low-resolution spectra, in observations of shocked gas from jets driven by Young Stellar Objects. In this paper we review this method, provide the relevant equations, and test it by analyzing high-resolution (R ∼ 50,000) NIR spectra of two young stars, namely the Herbig Be star HD 200775 and the Be star V1478 Cyg, which exhibit intense emission lines. The spectra were obtained with the new GIANO echelle spectrograph at the Telescopio Nazionale Galileo. Notably, the high-resolution spectra allowed checking the effects of overlapping telluric absorption lines. A set of various determinations of the Einstein coefficients are compared to show how much the available computations affect extinction derivation. The most recently obtained values are probably good enough to allow reddening determination within 1 visual mag of accuracy. Furthermore, we show that [Fe ii] line ratios from low-resolution pure emission-line spectra in general are likely to be in error due to the impossibility to properly account for telluric absorption lines. If low-resolution spectra are used for reddening determinations, we advice that the ratio 1.644/1.257, rather than 1.644/1.321, should be used, being less affected by the effects of telluric absorption lines. | URI: | http://hdl.handle.net/20.500.12386/26476 | URL: | https://iopscience.iop.org/article/10.1088/1538-3873/128/965/073001 | ISSN: | 0004-6280 | DOI: | 10.1088/1538-3873/128/965/073001 | Bibcode ADS: | 2016PASP..128g3001P | Fulltext: | open |
Appears in Collections: | 1.01 Articoli in rivista |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
ms_revised_postpr.pdf | preprint | 386.92 kB | Adobe PDF | View/Open |
Pecchioli_2016_PASP_128_073001.pdf | [Administrators only] | 628.73 kB | Adobe PDF |
Page view(s)
58
checked on Apr 26, 2024
Download(s)
15
checked on Apr 26, 2024
Google ScholarTM
Check
Altmetric
Altmetric
Items in DSpace are published in Open Access, unless otherwise indicated.