Exploring the properties of low-frequency radio emission and magnetic fields in a sample of compact galaxy groups using the LOFAR Two-Metre Sky Survey (LoTSS)

We use the LOFAR Two-metre Sky Survey (LoTSS) Data Release I to identify the groups of galaxies (and individual galaxies) from the Hickson compact groups (HCG) and magnitude-limited compact groups (MLCG) samples that emit at the frequency of 150 MHz, characterise their radio emission (extended or limited to the galaxies), and compare new results to earlier observations and theoretical predictions. The detection of 73 systems (and 7 more – probably) out of 120, of which as many as 17 show the presence of extended radio structures, confirms the previous hypothesis of the common character of the magnetic field inside galaxy groups and its detectability. In order to investigate the future potential of low-frequency radio studies of galaxy groups, we also present a more detailed insight into four radio-emitting systems, for which the strength of the magnetic field inside their intergalactic medium (IGM) is calculated. The estimated values are comparable to that found inside star-forming galaxies, suggesting a dynamical and evolutionary importance of the magnetic field in galaxy groups.

[1]  T. J. Dijkema,et al.  The LOFAR Two-metre Sky Survey. I. Survey description and preliminary data release , 2016, 1611.02700.

[2]  G. Helou,et al.  A Second “Taffy” Galaxy Pair , 2002 .

[3]  P. Hickson.  Systematic properties of compact groups of galaxies. , 1982 .

[4]  K. Chyzy,et al.  Magnetic field evolution in interacting galaxies , 2011, 1107.3280.

[5]  J. Hibbard,et al.  MID-INFRARED EVIDENCE FOR ACCELERATED EVOLUTION IN COMPACT GROUP GALAXIES , 2009, 1008.4581.

[6]  D. Gruijl.  BSc. Thesis , 2019 .

[7]  J. Hibbard,et al.  EXAMINING THE ROLE OF ENVIRONMENT IN A COMPREHENSIVE SAMPLE OF COMPACT GROUPS , 2012, 1201.1287.

[8]  V. Wild,et al.  Star formation and AGN activity in SDSS cluster galaxies , 2009, 0909.3522.

[9]  Bonn,et al.  Cosmic rays and the magnetic field of the nearby starburst galaxy NGC 253 , 2008, 0801.3542.

[10]  L. Verdes-Montenegro,et al.  Where is the neutral atomic gas in Hickson groups , 2001 .

[11]  J. Huchra,et al.  Dynamical properties of compact groups of galaxies , 1992 .

[12]  M. Hardcastle,et al.  A new method for finding and characterizing galaxy groups via low-frequency radio surveys , 2017, 1705.09510.

[13]  India.,et al.  Understanding `galaxy groups' as a unique structure in the universe , 2017, 1706.01916.

[14]  S. Markoff,et al.  LOFAR - low frequency array , 2006 .

[15]  G. Mamon,et al.  Compact groups from the Millennium Simulations – I. Their nature and the completeness of the Hickson sample , 2008 .

[16]  R. Nityananda,et al.  GMRT observations of the group Holmberg 124: Evolution by tidal forces and ram pressure? , 2005, astro-ph/0502036.

[17]  Richard L. White,et al.  The FIRST Survey: Faint Images of the Radio Sky at twenty centimeters , 1995 .

[18]  R. Beck,et al.  A search for extended radio emission from selected compact galaxy groups , 2017, 1705.06210.

[19]  G. Helou,et al.  The Taffy' galaxies UGC 12914/5 , 1993 .

[20]  X-RAY PROPERTIES OF GROUPS OF GALAXIES , 2000, astro-ph/0009379.

[21]  P. Prugniel,et al.  HyperLEDA. III. The catalogue of extragalactic distances , 2014, 1408.3476.

[22]  H. Rottgering,et al.  Deep LOFAR observations of the merging galaxy cluster CIZA J2242.8+5301 , 2017, 1706.09903.

[23]  E. Greisen,et al.  The NRAO VLA Sky Survey , 1996 .

[24]  J. Ables,et al.  Simultaneous observations of pulsar intensity variations at Parkes and Ootacamund. , 1974 .

[25]  N. Razavi-Ghods,et al.  Investigation of the cosmic ray population and magnetic field strength in the halo of NGC 891 , 2018, Astronomy & Astrophysics.

[26]  Revised equipartition and minimum energy formula for magnetic field strength estimates from radio synchrotron observations , 2005, astro-ph/0507367.

[27]  T. J. Dijkema,et al.  LOFAR, VLA, AND CHANDRA OBSERVATIONS OF THE TOOTHBRUSH GALAXY CLUSTER , 2016, 1601.06029.

[28]  M. Geller,et al.  CATALOGS OF COMPACT GROUPS OF GALAXIES FROM THE ENHANCED SDSS DR12 , 2016, 1603.06583.

[29]  A. Basu,et al.  Exploring the making of a galactic wind in the starbursting dwarf irregular galaxy IC 10 with LOFAR , 2018, 1802.01463.

[30]  J. Conway,et al.  The nature of the low-frequency emission of M 51 , 2014, Astronomy & Astrophysics.

[31]  M. Krause,et al.  The large scale magnetic field structure of the spiral galaxy NGC 5775 , 2011, 1105.5259.

[32]  M. Krause.  Magnetic Fields and Halos in Spiral Galaxies , 2014, Galaxies.

[33]  National Radio Astronomy Observatory,et al.  GALAXY EVOLUTION IN A COMPLEX ENVIRONMENT: A MULTI-WAVELENGTH STUDY OF HCG 7 , 2010, 1007.3523.

[34]  F. Owen,et al.  Head-tail radio sources in clusters of galaxies , 1976 .

[35]  R. Beck,et al.  The equipartition magnetic field formula in starburst galaxies: accounting for pionic secondaries and strong energy losses , 2013, 1301.5391.

[36]  D. Frail,et al.  The GMRT 150 MHz all-sky radio survey - First alternative data release TGSS ADR1 , 2016, 1603.04368.

[37]  H. Rottgering,et al.  LOFAR MSSS: Discovery of a 2.56 Mpc giant radio galaxy associated with a disturbed galaxy group , 2017, 1702.01571.

[38]  P. Mazzotta,et al.  A COMBINED LOW-RADIO FREQUENCY/X-RAY STUDY OF GALAXY GROUPS. I. GIANT METREWAVE RADIO TELESCOPE OBSERVATIONS AT 235 MHz AND 610 MHz , 2011, 1103.1364.

[39]  L. Danly.  The Interstellar Disk-Halo Connection , 1993 .

[40]  Eck,et al.  Revised equipartition and minimum energy formula for magnetic field strength estimates from radio synchrotron observations , 2005, astro-ph/0507367.

[41]  D. A. García-Hernández,et al.  University of Birmingham The Fourteenth Data Release of the Sloan Digital Sky Survey: , 2017 .

[42]  J. Riley,et al.  The Morphology of Extragalactic Radio Sources of High and Low Luminosity , 1974 .

[43]  G. Abell.  The Distribution of rich clusters of galaxies , 1958 .

[44]  H. Bloemen.  The Interstellar Disk-Halo Connection in Galaxies , 1991 .

[45]  P. Hickson,et al.  Radio sources in dense groups , 1985 .

[46]  I. Konstantopoulos,et al.  THE OPTICAL GREEN VALLEY VERSUS MID-INFRARED CANYON IN COMPACT GROUPS , 2013, 1307.6559.

[47]  G. Vaucouleurs,et al.  Third Reference Catalogue of Bright Galaxies , 2012 .

[48]  R. Beck,et al.  Intergalactic magnetic fields in Stephan's Quintet , 2013, 1307.3447.

[49]  James R. Curran,et al.  blobcat: software to catalogue flood‐filled blobs in radio images of total intensity and linear polarization , 2012, 1205.5313.

[50]  H. Arp.  A Grouping of Radio Sources in the Area of NGC 7331 and Stephan's Quintet , 1972 .