X-Ray Polarization of BL Lacertae in Outburst
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F23%3A00574030" target="_blank" >RIV/67985815:_____/23:00574030 - isvavai.cz</a>
Result on the web
<a href="https://hdl.handle.net/11104/0344391" target="_blank" >https://hdl.handle.net/11104/0344391</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.3847/2041-8213/acd242" target="_blank" >10.3847/2041-8213/acd242</a>
Alternative languages
Result language
angličtina
Original language name
X-Ray Polarization of BL Lacertae in Outburst
Original language description
We report the first >99% confidence detection of X-ray polarization in BL Lacertae. During a recent X-ray/γ-ray outburst, a 287 ks observation (2022 November 27-30) was taken using the Imaging X-ray Polarimetry Explorer (IXPE), together with contemporaneous multiwavelength observations from the Neil Gehrels Swift observatory and XMM-Newton in soft X-rays (0.3-10 keV), NuSTAR in hard X-rays (3-70 keV), and optical polarization from the Calar Alto and Perkins Telescope observatories. Our contemporaneous X-ray data suggest that the IXPE energy band is at the crossover between the low- and high-frequency blazar emission humps. The source displays significant variability during the observation, and we measure polarization in three separate time bins. Contemporaneous X-ray spectra allow us to determine the relative contribution from each emission hump. We find >99% confidence X-ray polarization Π2--4keV=21.7+5.6−7.9% and electric vector polarization angle ψ 2-4keV = -28.°7 ± 8.°7 in the time bin with highest estimated synchrotron flux contribution. We discuss possible implications of our observations, including previous IXPE BL Lacertae pointings, tentatively concluding that synchrotron self-Compton emission dominates over hadronic emission processes during the observed epochs.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10308 - Astronomy (including astrophysics,space science)
Result continuities
Project
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Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2023
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Astrophysical Journal Letters
ISSN
2041-8205
e-ISSN
2041-8213
Volume of the periodical
948
Issue of the periodical within the volume
2
Country of publishing house
US - UNITED STATES
Number of pages
12
Pages from-to
L25
UT code for WoS article
000992537100001
EID of the result in the Scopus database
2-s2.0-85159697882