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J/A+A/609/A78       MUSE combined data cubes for NGC 3311       (Barbosa+, 2018)

Sloshing in its cD halo: MUSE kinematics of the central galaxy NGC 3311 in the Hydra I cluster. Barbosa C.E., Arnaboldi A., Coccato L., Gerhard O., Mendes de Oliveira C., Hilker M., Richtler T. <Astron. Astrophys. 609, A78 (2018)> =2018A&A...609A..78B (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, optical Keywords: galaxies: clusters: individual: Hydra I - galaxies: individual: NGC 3311 - galaxies: elliptical and lenticular, cD - galaxies: kinematics and dynamics - galaxies: structure - galaxies: stellar content Abstract: Early-type galaxies (ETGs) show a strong size evolution with redshift. This evolution is explained by fast "in-situ" star formation at high-z followed by a late mass assembly mostly driven by minor mergers that deposit stars primarily in the outer halo. Aims: We aim to identify the main structural components of the Hydra I cD galaxy NGC 3311 to investigate the connection between the central galaxy and the surrounding stellar halo. We produce maps of the line-of-sight velocity distribution (LOSVD) moments from a mosaic of MUSE pointings covering NGC 3311 out to 25kpc. Combining deep photometric and spectroscopic data, we model the LOSVD maps using a finite mixture distribution, including four non-concentric components that are nearly isothermal spheroids, with different line-of-sight systemic velocities V, velocity dispersions sigma, and small (constant) values of the higher order Gauss-Hermite moments h3 and h4. The kinemetry analysis indicates that NGC 3311 is classified as a slow rotator, although the galaxy shows a line-of-sight velocity gradient along the photometric major axis. The comparison of the correlations between h3 and h4 with Vσ with simulated galaxies indicates that NGC 3311 assembled mainly through dry mergers. The sigma profile rises to approximately 400$ km/s at 20kpc, a significant fraction (0.55) of the Hydra I cluster velocity dispersion, indicating that stars there were stripped from progenitors orbiting in the cluster core. The finite mixture distribution modeling supports three inner components related to the central galaxy and a fourth component with large effective radius (51kpc) and velocity dispersion (327km/s) consistent with a cD envelope. We find that the cD envelope is offset from the center of NGC 3311 both spatially (8.6kpc) and in velocity (δV=204km/s), but coincides with the cluster core X-ray isophotes and the mean velocity of core galaxies. Also, the envelope contributes to the broad wings of the LOSVD measured by large h_4 values within 10 kpc. The cD envelope of NGC 3311 is dynamically associated with the cluster core, which in Hydra I is in addition displaced from the cluster center, presumably due to a recent subcluster merger. Description: Combined MUSE data cubes for four fields of NGC 3311. Original data is available at the ESO archive, identified by the program ID 094.B-0711(A). All relevant technical data are included in the FITS header of the data cube. The flux units are in [ergs/s/cm2/Angstrom]. Objects: ------------------------------------------------------ RA (2000) DE Designation(s) ------------------------------------------------------ 10 36 42.82 -27 31 42.0 NGC 3311 = ESO 501-38 ------------------------------------------------------ File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file list.dat 177 4 List of fits datacubes fits/* 0 4 Individual datacubes
See also: J/A+A/589/A139 : Stellar populations of NGC 3311 (Barbosa+, 2016) Byte-by-byte Description of file: list.dat
Bytes Format Units Label Explanations
1- 9 F9.5 deg RAdeg Right Ascension of center (J2000) 10- 18 F9.5 deg DEdeg Declination of center (J2000) 20- 22 F3.1 arcsec/pix scale Scale of the image 24- 26 I3 --- Nx Number of pixels along X-axis 28- 30 I3 --- Ny Number of pixels along Y-axis 32- 35 I4 --- Nz Number of slices 37- 59 A23 --- Observation date ( 61- 67 F7.2 0.1nm blambda Lower value of wavelength interval 69- 75 F7.2 0.1nm Blambda Upper value of wavelength interval 77- 80 F4.2 0.1nm dlambda Wavelength resolution 82- 88 I7 Kibyte size Size of FITS file 90-152 A63 --- FileName Name of FITS file, in subdirectory fits 154-177 A24 --- Title Title of the FITS file
Acknowledgements: Carlos E. Barbosa, carlos.barbosa(at)
(End) Carlos E. Barbosa [USP-IAG], Patricia Vannier [CDS] 09-Nov-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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