J/A+A/693/A55 CL0238.3+2005 RTT-150 composite rizw image (Lyskova+, 2025)
The massive galaxy cluster CL0238.3+2005 (the Peanut cluster) at z=0.42:
A merger just after pericenter passage?
Lyskova N., Churazov E., Khabibullin I., Bikmaev I.F., Burenin R.A.,
Forman W.R., Khamitov I.M., Rajpurohit K., Sunyaev R., Jones C., Kraft R.,
Zaznobin I., Gorbachev M.A., Suslikov M.V., Gumerov R.I., Sakhibullin N.A.
<Astron. Astrophys. 693, A55 (2025)>
=2025A&A...693A..55L 2025A&A...693A..55L (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Redshifts ; Optical
Keywords: galaxies: clusters: intracluster medium -
galaxies: distances and redshifts -
galaxies: clusters: individual: CL0238.3+2005
Abstract:
Massive clusters of galaxies are very rare in the observable Universe.
Mergers of such clusters observed close to pericenter passage are
even rarer. Here, we report on one such case: The massive
(∼1015,M☉ and hot (kT∼10keV) cluster CL0238.3+2005 at z=0.42.
For this cluster, we combined X-ray data from SRG/eROSITA and Chandra,
optical images from DESI, and spectroscopy from the BTA and RTT-150
telescopes. The X-ray and optical morphologies suggest an ongoing
merger with a projected separation of the subhalos of ∼200kpc. The
line-of-sight velocity of galaxies that are tentatively associated
with the two merging halos differs by 2000-3000km/s. We conclude that
the merger axis is most likely neither close to the line of sight nor
to the sky plane. We compare CL0238 with the two well-known clusters
MACS0416 and the Bullet and conclude that CL0238 corresponds to an
intermediate phase between the pre-merging MACS0416 cluster and the
post-merger Bullet cluster. Namely, this cluster recently (only
~=0.1Gyr ago) experienced an almost head-on merger. We argue that
this "just after" system is a very rare case and an excellent target
for lensing, the Sunyaev-Zeldovich effect, and X-ray studies that can
constrain properties ranging from dynamics of mergers to
self-interacting dark matter, and plasma effects in the intracluster
medium that are associated with shock waves, for instance,
electron-ion equilibration efficiency and relativistic particle
acceleration.
Description:
We present spectroscopic redshifts of brightest individual galaxies in
CL0238 and the RTT-150 composite rizw image.
Objects:
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RA (2000) DE Designation(s)
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02 38 20.8 +20 05 56 SRGe CL0238.3+2005 = [WHL2012] J023820.7+200619
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 48 6 Spectroscopic redshifts of individual galaxies
in CL0238.3+2005
list.dat 134 1 Informations on fits image
fits/* . 1 fits image
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 F7.4 deg RAdeg Right Ascension (J2000)
9- 16 F8.4 deg DEdeg Declination (J2000)
18- 23 F6.4 --- z Galaxy redshift
25- 30 F6.4 --- e_z Redshift uncertainty
32- 36 I5 km/s Vlos Galaxy line-of-sight velocity with respect to
the mean cluster redshift =0.4191
38- 40 I3 km/s e_Vlos Uncertainty on line-of-sight velocity
42- 48 A7 --- Tel Optical telescope (BTA or RTT-150)
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 24 F5.3 arcsec/pix scale Scale of the image
26- 29 I4 --- Nx Number of pixels along X-axis
31- 34 I4 --- Ny Number of pixels along Y-axis
36- 57 A22 "datime" Obs.date Observation date
59- 63 I5 Kibyte size Size of FITS file
65- 91 A27 --- FileName Name of FITS file, in subdirectory fits
93-134 A42 --- Title Title of the FITS file
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Acknowledgements:
Natalia Lyskova, natalya.lyskova(at)gmail.com
(End) Patricia Vannier [CDS] 29-Nov-2024