2015A&A...579A..27S


C.D.S. - SIMBAD4 rel 1.7 - 2020.07.13CEST06:34:41

2015A&A...579A..27S - Astronomy and Astrophysics, volume 579A, 27-27 (2015/7-1)

The peculiar radio galaxy 4C 35.06: a case for recurrent AGN activity?

SHULEVSKI A., MORGANTI R., BARTHEL P.D., MURGIA M., VAN WEEREN R.J., WHITE G.J., BRUEGGEN M., KUNERT-BAJrASZEWSKA M., JAMROZY M., BEST P.N., ROETTGERING H.J.A., CHYZY K.T., DE GASPERIN F., BIRZAN L., BRUNETTI G., BRIENZA M., RAFFERTY D.A., ANDERSON J., BECK R., DELLER A., ZARKA P., SCHWARZ D., MAHONY E., ORRU E., BELL M.E., BENTUM M.J., BERNARDI G., BONAFEDE A., BREITLING F., BRODERICK J.W., BUTCHER H.R., CARBONE D., CIARDI B., DE GEUS E., DUSCHA S., EISLOEFFEL J., ENGELS D., FALCKE H., FALLOWS R.A., FENDER R., FERRARI C., FRIESWIJK W., GARRETT M.A., GRIESSMEIER J., GUNST A.W., HEALD G., HOEFT M., HOERANDEL J., HORNEFFER A., VAN DER HORST A.J., INTEMA H., JUETTE E., KARASTERGIOU A., KONDRATIEV V.I., KRAMER M., KUNIYOSHI M., KUPER G., MAAT P., MANN G., McFADDEN R., McKAY-BUKOWSKI D., McKEAN J.P., MEULMAN H., MULCAHY D.D., MUNK H., NORDEN M.J., PAAS H., PANDEY-POMMIER M., PIZZO R., POLATIDIS A.G., REICH W., ROWLINSON A., SCAIFE A.M.M., SERYLAK M., SLUMAN J., SMIRNOV O., STEINMETZ M., SWINBANK J., TAGGER M., TANG Y., TASSE C., THOUDAM S., TORIBIO M.C., VERMEULEN R., VOCKS C., WIJERS R.A.M.J., WISE M.W. and WUCKNITZ O.

Abstract (from CDS):

Using observations obtained with the LOw Fequency ARray (LOFAR), the Westerbork Synthesis Radio Telescope (WSRT) and archival Very Large Array (VLA) data, we have traced the radio emission to large scales in the complex source 4C 35.06 located in the core of the galaxy cluster Abell 407. At higher spatial resolution (∼4"), the source was known to have two inner radio lobes spanning 31kpc and a diffuse, low-brightness extension running parallel to them, offset by about 11kpc (in projection). At 62MHz, we detect the radio emission of this structure extending out to 210kpc. At 1.4GHz and intermediate spatial resolution (∼30"), the structure appears to have a helical morphology. We have derived the characteristics of the radio spectral index across the source. We show that the source morphology is most likely the result of at least two episodes of AGN activity separated by a dormant period of around 35Myr. The outermost regions of radio emission have a steep spectral index (α< -1), indicative of old plasma. We connect the spectral index properties of the resolved source structure with the integrated flux density spectral index of 4C 35.06 and suggest an explanation for its unusual integrated flux density spectral shape (a moderately steep power law with no discernible spectral break), possibly providing a proxy for future studies of more distant radio sources through inferring their detailed spectral index properties and activity history from their integrated spectral indices. The AGN is hosted by one of the galaxies located in the cluster core of Abell 407. We propose that it is intermittently active as it moves in the dense environment in the cluster core. In this scenario, the AGN turned on sometime in the past, and has produced the helical pattern of emission, possibly a sign of jet precession/merger during that episode of activity. Using LOFAR, we can trace the relic plasma from that episode of activity out to greater distances from the core than ever before. Using the the WSRT, we detect HI in absorption against the center of the radio source. The absorption profile is relatively broad (FWHM of 288km/s), similar to what is found in other clusters. The derived column density is NHI∼4x1020cm –2 for a Tspin=100K. This detection supports the connection - already suggested for other restarted radio sources - between the presence of cold gas and restarting activity. The cold gas appears to be dominated by a blue-shifted component although the broad HI profile could also include gas with different kinematics. Understanding the duty cycle of the radio emission as well as the triggering mechanism for starting (or restarting) the radio-loud activity can provide important constraints to quantify the impact of AGN feedback on galaxy evolution. The study of these mechanisms at low frequencies using morphological and spectral information promises to bring new important insights in this field.

Abstract Copyright:

Journal keyword(s): radio continuum: galaxies - galaxies: active - radio lines: galaxies - galaxies: individual: 4C 35.06

Simbad objects: 15

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Number of rows : 15

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 NGC 1167 LIN 03 01 42.358 +35 12 20.34   13.84 12.77     ~ 297 2
2 ACO 407 ClG 03 01 43.7 +35 49 48           ~ 104 0
3 UGC 2489 GiC 03 01 51.4 +35 50 23           ~ 171 1
4 UGC 2493 GiC 03 02 01.492 +35 45 35.36   15.5       ~ 15 0
5 SDSS J030217.60+355532.5 ? 03 02 17.609 +35 55 32.51           ~ 1 0
6 SDSS J030218.01+354556.1 ? 03 02 18.012 +35 45 56.16           ~ 1 0
7 NAME Hya A LIN 09 18 05.651 -12 05 43.99   14.38 14.8     ~ 908 1
8 MCG+05-33-005 LIN 13 48 52.511 +26 35 34.84   14.0       ~ 220 2
9 ACO 1795 ClG 13 49 00.5 +26 35 07           ~ 1154 0
10 ACO 1835 ClG 14 01 02.07 +02 52 43.2           ~ 621 1
11 ACO 2199 ClG 16 28 37.0 +39 31 28           ~ 1101 1
12 3C 338.0 QSO 16 28 38.2443686587 +39 33 04.231770853   12.78 11.78     ~ 702 5
13 NAME Cyg A Sy2 19 59 28.35645829 +40 44 02.0966496   16.22 15.10     ~ 2113 2
14 ACO 2597 ClG 23 25 19.70 -12 07 27.7           ~ 493 0
15 2E 4728 LIN 23 25 19.731 -12 07 27.51   15.45 15.46     ~ 169 2

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2020.07.13-06:34:41

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