IXPE observation of PKS 2155–304 reveals the most highly polarized blazar

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F24%3A00598913" target="_blank" >RIV/67985815:_____/24:00598913 - isvavai.cz</a>

Result on the web

<a href="https://hdl.handle.net/11104/0356485" target="_blank" >https://hdl.handle.net/11104/0356485</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202449166" target="_blank" >10.1051/0004-6361/202449166</a>

Result language

angličtina

Original language name

IXPE observation of PKS 2155–304 reveals the most highly polarized blazar

Original language description

We report the X-ray polarization properties of the high-synchrotron-peaked (HSP) blazar PKS 2155'304 based on observations with the Imaging X-ray Polarimetry Explorer (IXPE). We observed the source between Oct 27 and Nov 7, 2023. We also conducted an extensive contemporaneous multiwavelength (MW) campaign. We find that during the first half (T1) of the IXPE pointing, the source exhibited the highest X-ray polarization degree detected for an HSP blazar thus far, (30.7 ± 2.0)%, this dropped to (15.3 ± 2.1)% during the second half (T2). The X-ray polarization angle remained stable during the IXPE pointing at 129.4 '±1.8 and 125.4 '±3.9 during T1 and T2, respectively. Meanwhile, the optical polarization degree remained stable during the IXPE pointing, with average host-galaxy-corrected values of (4.3 ± 0.7)% and (3.8 ± 0.9)% during the T1 and T2, respectively. During the IXPE pointing, the optical polarization angle changed achromatically from 140 to 90 and back to 130. Despite several attempts, we only detected (99.7% conf.) the radio polarization once (during T2, at 225.5 GHz): with degree (1.7 ± 0.4)% and angle 112.5 '±5.5. The direction of the broad pc-scale jet is rather ambiguous and has been found to point to the east and south at different epochs, however, on larger scales (> 1.5 pc) the jet points toward the southeast ( 135), similarly to all of the MW polarization angles. Moreover, the X-ray-to-optical polarization degree ratios of 7 and 4 during T1 and T2, respectively, are similar to previous IXPE results for several HSP blazars. These findings, combined with the lack of correlation of temporal variability between the MW polarization properties, agree with an energy-stratified shock-acceleration scenario in HSP blazars.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astronomy & Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Volume of the periodical

689

Issue of the periodical within the volume

Sept.

Country of publishing house

FR - FRANCE

Number of pages

17

Pages from-to

A119

UT code for WoS article

001318739000001

EID of the result in the Scopus database

2-s2.0-85200258826