TY  - JOUR
A1  - Furniss, Amy
A1  - Worseck, Gabor
A1  - Fumagalli, Michele
A1  - Johnson, Caitlin A.
A1  - Williams, David A.
A1  - Pontrelli, P.
A1  - Prochaska, J. Xavier
T1  - Spectroscopic Redshift of the Gamma-Ray Blazar B2 1215+30 from Ly alpha Emission
T2  - The astronomical journal
N2  - 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.
KW  - galaxies:distances and redshifts
KW  - galaxies: individual (B2 1215+30)
KW  - gamma rays: galaxies
KW  - ultraviolet: galaxies
Y1  - 2019
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/50388
SN  - 0004-6256
SN  - 1538-3881
VL  - 157
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  -