Spectroscopic Redshift of the Gamma-Ray Blazar B2 1215+30 from Lyα Emission

Furniss, A.; Worseck, G.; Fumagalli, M.; Johnson, C.A.; Williams, D.A.; Pontrelli, P.; Prochaska, J.X.

doi:10.3847/1538-3881/aaf28b

Spectroscopic Redshift of the Gamma-Ray Blazar B2 1215+30 from Lyα Emission

Furniss, A.; Worseck, G.; Fumagalli, M.; Johnson, C.A.; Williams, D.A.; Pontrelli, P.; Prochaska, J.X.

Authors

A. Furniss

G. Worseck

Professor Michele Fumagalli michele.fumagalli@durham.ac.uk
Academic Visitor

C.A. Johnson

D.A. Williams

P. Pontrelli

J.X. Prochaska

Abstract

We report on Cosmic Origin Spectrograph observations of the gamma-ray bright blazar B2 1215+30, collected in 2015 November. These observations allow for the confirmation of the source redshift from the detection of a Lyα emission feature at λ ~ 1374 Å. The emission feature places the source at a redshift of z = 0.1305 ± 0.003, confirming the source's ground-based spectral measurement. The gamma-ray emission of the source is discussed in the context of the source distance, required for the accurate reconstruction of the intrinsic gamma-ray emission taking the absorption by the extragalactic background light into account. The source distance is found to be low enough that the previously reported detection of an exceptional flaring event from B2 1215+30 in 2014 cannot be used to investigate opacity-specific spectral and variability characteristics introduced by possible ultra-high-energy cosmic-ray propagation.

Citation

Furniss, A., Worseck, G., Fumagalli, M., Johnson, C., Williams, D., Pontrelli, P., & Prochaska, J. (2019). Spectroscopic Redshift of the Gamma-Ray Blazar B2 1215+30 from Lyα Emission. Astronomical Journal, 157(2), Article 41. https://doi.org/10.3847/1538-3881/aaf28b

Journal Article Type	Article
Acceptance Date	Nov 18, 2018
Online Publication Date	Jan 7, 2019
Publication Date	Jan 7, 2019
Deposit Date	Jan 23, 2019
Publicly Available Date	Jan 23, 2019
Journal	Astronomical Journal
Print ISSN	0004-6256
Publisher	IOP Publishing
Peer Reviewed	Peer Reviewed
Volume	157
Issue	2
Article Number	41
DOI	https://doi.org/10.3847/1538-3881/aaf28b

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