2022A&A...661A..26I


Query : 2022A&A...661A..26I

2022A&A...661A..26I - Astronomy and Astrophysics, volume 661A, 26-26 (2022/5-1)

eROSITA spectro-imaging analysis of the Abell 3408 galaxy cluster.

ILJENKAREVIC J., REIPRICH T.H., PACAUD F., VERONICA A., WHELAN B., ASCHERSLEBEN J., MIGKAS K., BULBUL E., SANDERS J.S., RAMOS-CEJA M.E., LIU T., GHIRARDINI V., LIU A. and BOLLER T.

Abstract (from CDS):


Context. The X-ray telescope eROSITA on board the newly launched Spectrum-Roentgen-Gamma (SRG) mission serendipitously observed the galaxy cluster Abell 3408 (A3408) during the performance verification observation of the active galactic nucleus 1H 0707-495. The field of view of eROSITA is one degree, which allowed us to trace the intriguing elongated morphology of the nearby (z = 0.0420) A3408 cluster. Despite its brightness (F500 ~= 7 x 10–12 ergs s–1 cm–2) and large extent (r200 ~= 21'), it has not been observed by any modern X-ray observatory in over 20 yr. A neighboring cluster in the NW direction, A3407 (r200 ~= 18', z = 0.0428), appears to be close at least in projection (∼1.7 Mpc). This cluster pair might be in a pre- or post-merger state.
Aims. We aim to determine the detailed thermodynamical properties of this special cluster system for the first time. Furthermore, we aim to determine which of the previously suggested merger scenarios (pre- or post-merger) is preferred.
Methods. We performed a detailed X-ray spectro-imaging analysis of A3408. We constructed particle-background-subtracted and exposure-corrected images and surface brightness profiles in different sectors. The spectral analysis was performed out to 1.4r500 and included normalization, temperature, and metallicity profiles determined from elliptical annuli aligned with the elongation of A3408. Additionally, a temperature map is presented that depicts the distribution of the intracluster medium (ICM) temperature. Furthermore, we make use of data from the ROSAT all-sky survey to estimate some bulk properties of A3408 and A3407, using the growth-curve analysis method and scaling relations.
Results. The imaging analysis shows the complex morphology of A3408 with a strong elongation in the SE-NW direction. This is quantified by comparing the surface brightness profiles of the NW, SW, SE, and NE directions, where the NW and SE directions show a significantly higher surface brightness than the other directions. We determine a gas temperature kBr500=(2.23±0.09)keV in the range 0.2r500 to 0.5r500 from the spectral analysis. The temperature profile reveals a hot core within two arcminutes of the emission peak, kBT=3.04–0.25+0.29keV. Employing a mass-temperature relation, we obtain M500 = (9.27 ± 0.75) x 1013M iteratively. The r200 of A3407 and A3408 are found to overlap in projection, which makes ongoing interactions plausible. The two-dimensional temperature map reveals higher temperatures in the W than in the E direction.
Conclusions. The elliptical morphology together with the temperature distribution suggests that A3408 is an unrelaxed system. The system A3407 and A3408 is likely in a pre-merger state, with some interactions already affecting the ICM thermodynamical properties. In particular, increased temperatures in the direction of A3407 indicate adiabatic compression or shocks due to the starting interaction.

Abstract Copyright: © ESO 2022

Journal keyword(s): clusters: individual: Abell 3408 - galaxies: clusters: intracluster medium - X-rays: galaxies: clusters - intergalactic medium

Simbad objects: 11

goto Full paper

goto View the references in ADS

Number of rows : 11
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 ACO 399 ClG 02 57 56.4 +13 00 59           ~ 373 0
2 ACO 3391 ClG 06 26 15.4 -53 40 52           ~ 185 1
3 ACO 3407 ClG 07 05 01 -49 04.6           ~ 19 0
4 2MASX J07081135-4909525 BiC 07 08 11.4190342776 -49 09 53.029147104       13.50   ~ 9 0
5 2MASX J07082956-4912505 BiC 07 08 29.562 -49 12 50.53   14.85   13.35   ~ 13 1
6 ACO 3408 ClG 07 08 31 -49 12.9           ~ 21 0
7 LEDA 88588 Sy1 07 08 41.4886614696 -49 33 06.308921700   16.02 15.7 12.7   ~ 466 0
8 2MASX J07105736-4914165 G 07 10 57.3664408392 -49 14 16.096095420   15.68   14.37   ~ 8 0
9 ACO 1758 ClG 13 32 32.1 +50 30 37           ~ 238 2
10 ACO 2029 ClG 15 10 58.7 +05 45 42           ~ 896 0
11 NAME LHB X 16 42.0 +02 19           ~ 296 0

To bookmark this query, right click on this link: simbad:objects in 2022A&A...661A..26I and select 'bookmark this link' or equivalent in the popup menu


2022.08.09-15:50:09

© Université de Strasbourg/CNRS

    • Contact