3 research outputs found
Collimated synchrotron threads linking the radio lobes of ESO 137-006
We present MeerKAT 1000 MHz and 1400 MHz observations of a bright radio galaxy in the southern hemisphere, ESO 137-006. The
galaxy lies at the centre of the massive and merging Norma galaxy cluster. The MeerKAT continuum images (rms ∼0.02 mJy beam−1
at ∼1000 resolution) reveal new features that have never been seen in a radio galaxy before: collimated synchrotron threads of yet
unknown origin, which link the extended and bent radio lobes of ESO 137-006. The most prominent of these threads stretches in
projection for about 80 kpc and is about 1 kpc in width. The radio spectrum of the threads is steep, with a spectral index of up to α ' 2
between 1000 and 1400 MHz.http://www.aanda.orgpm2021Physic
GASP XXVI. HI gas in jellyfish galaxies : the case of JO201 and JO206
Please read abstract in the article.European
Research Council (ERC) under the European Union’s Horizon 2020 research
and innovation programme grant agreement no. 679627 and no.833824,
project name FORNAX and GASP, respectively. We acknowledge funding from
the agreement ASI-INAF n.2017-14-H.0, as well as from the INAF main-stream
funding programme. M. R’s research is supported by the SARAO HCD programme
via the "New Scientific Frontiers with Precision Radio Interferometry"
research group grant. M. R. acknowledges support from the Italian Ministry
of Foreign A airs and International Cooperation (MAECI Grant Number
ZA18GR02) and the South African Department of Science and Technology’s
National Research Foundation (DST-NRF Grant Number 113121) as
part of the ISARP RADIOSKY2020 Joint Research Scheme. B. V. and M. G.
also acknowledge the Italian PRIN-Miur 2017 (PI A. Cimatti). Y. J. acknowledges
financial support from CONICYT PAI (Concurso Nacional de Insercion
en la Academia 2017), No. 79170132 and FONDECYT Iniciación 2018 No.
11180558. M. V. acknowledges support by the Netherlands Foundation for Scientific
Research (NWO) through VICI grant 016.130.338.http://www.aanda.orgam2020Physic
GASP:XXVI. HI Gas in Jellyfish Galaxies: The case of JO201 and JO206
We present HI observations of the jellyfish galaxy, JO201. This massive
galaxy (M M) is falling along the
line-of-sight towards the centre of a rich cluster (M M, km/s) at a high velocity 3363
km/s. Its H emission shows a 40 kpc tail confined closely to its
stellar disc and a 100 kpc tail extending further out. We find HI
emission coinciding only with the shorter clumpy H tail. In total, we
measure an HI mass of M M, which is
about 60% lower than expected based on its stellar mass and stellar surface
density. We compared JO201 to another jellyfish in the GASP sample, JO206 (of
similar mass but residing in a 10 less massive cluster), and find that
they are similarly HI-deficient. Of the total HI mass in JO201, about 30% lies
outside the galaxy disc in projection. This HI fraction is probably a lower
limit since most of the HI is redshifted relative to the stellar disc and could
be outside the disc. The global star formation rate (SFR) analysis of JO201
suggests that its observed SFR would be expected if it had 10 its
current HI mass. The disc is the main contributor of the high star formation
efficiency at a given HI gas density for both galaxies, but their tails also
show higher star formation efficiencies compared to the outer regions of field
galaxies. Generally, we find that JO201 and JO206 are similar based on their HI
content, stellar mass and star formation rate. This finding is unexpected
considering their different environments. A toy model comparing the ram
pressure of the ICM versus the restoring forces of these galaxies suggests that
the ram pressure strength exerted on them could be comparable if we consider
their 3D orbital velocities and radial distances relative to the clusters.Comment: 9 pages, 8 figures, Accepted for publication in A&