J 2024

Ram-pressure stripped radio tail and two ULXs in the spiral galaxy HCG 97b

HU, Dan, Michal ZAJAČEK, Norbert WERNER, Romana GROSSOVÁ, Pavel JÁCHYM et. al.

Basic information

Original name

Ram-pressure stripped radio tail and two ULXs in the spiral galaxy HCG 97b

Authors

HU, Dan (156 China, guarantor, belonging to the institution), Michal ZAJAČEK (703 Slovakia, belonging to the institution), Norbert WERNER (703 Slovakia, belonging to the institution), Romana GROSSOVÁ (703 Slovakia, belonging to the institution), Pavel JÁCHYM, Ian D ROBERTS, Alessandro IGNESTI, D P Kenney KENNEY, Tomáš PLŠEK (203 Czech Republic, belonging to the institution), Jean-Paul Bernhard RIFFALD SOUZA BREUER (76 Brazil, belonging to the institution), Timothy SHIMWELL, Cyril TASSE, Zhenghao ZHU and Linhui WU

Edition

Monthly Notices of the Royal Astronomical Society, Oxford University Press, 2024, 0035-8711

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10308 Astronomy

Country of publisher

United Kingdom of Great Britain and Northern Ireland

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

Impact factor

Impact factor: 4.800 in 2022

Organization unit

Faculty of Science

UT WoS

001102991000006

Keywords in English

galaxies: individual: HCG 97b; galaxies: interactions; radio continuum: galaxies

Tags

Tags

International impact, Reviewed
Změněno: 6/2/2024 09:00, Mgr. Marie Šípková, DiS.

Abstract

V originále

We report LOFAR and VLA detections of extended radio emission in the spiral galaxy HCG 97b, hosted by an X-ray bright galaxy group. The extended radio emission detected at 144 MHz, 1.4 GHz and 4.86 GHz is elongated along the optical disk and has a tail that extends 27 kpc in projection towards the centre of the group at GHz frequencies or 60 kpc at 144 MHz. Chandra X-ray data show two off-nuclear ultra-luminous X-ray sources (ULXs), with the farther one being a plausible candidate for an accreting intermediate-mass black hole (IMBH). The asymmetry observed in both CO emission morphology and kinematics indicates that HCG 97b is undergoing ram-pressure stripping, with the leading side at the southeastern edge of the disk. Moreover, the VLA 4.86 GHz image reveals two bright radio blobs near one ULX, aligning with the disk and tail, respectively. The spectral indices in the disk and tail are comparable and flat (α>−1), suggesting the presence of recent outflows potentially linked to ULX feedback. This hypothesis gains support from estimates showing that the bulk velocity of the relativistic electrons needed for transport from the disk to the tail is approximately ∼1300 km s−1. This velocity is much higher than those observed in ram-pressure stripped galaxies (100−600 km s−1), implying an alternative mechanism aiding the stripping process. Therefore, we conclude that HCG 97b is subject to ram pressure, with the formation of its stripped radio tail likely influenced by the putative IMBH activities.

Links

GX21-13491X, research and development project
Name: Zkoumání žhavého vesmíru a porozumění kosmické zpětné vazbě (Acronym: EHU)
Investor: Czech Science Foundation
90106, large research infrastructures
Name: EU-ARC.CZ II