J/A+A/621/A25 Arp 240 Fabry-Perot interferometry (Fuentes-Carrera+, 2019)
Kinematics and dynamics of the luminous infrared galaxy pair
NGC 5257/58 (Arp 240).
Fuentes-Carrera I., Rosado M., Amram P., Laurikainen E., Salo H.,
Gomez-Lopez J.A., Castaneda H.O., Bernal A., Balkowski C.
<Astron. Astrophys. 621, A25 (2019)>
=2019A&A...621A..25F 2019A&A...621A..25F (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, optical; Galaxies, peculiar; Galaxies, rotation
Keywords: galaxies: interactions - galaxies: kinematics and dynamics -
galaxies: spiral - galaxies: star formation -
galaxies: individual: NGC 5257 - galaxies: individual: NGC 5258
Abstract:
Encounters between galaxies modify their morphology, kinematics, and
star formation history. The relation between these changes and
external perturbations is not straightforward.
The great number of parameters involved requires both the study of
large samples and individual encounters where particular features,
motions, and perturbations can be traced and analysed in detail.
We analysed the morphology, kinematics, and dynamics of two luminous
infrared spiral galaxies of almost equal mass, NGC 5257 and NGC 5258,
in which star formation is mostly confined to the spiral arms, in
order to understand interactions between galaxies of equivalent masses
and star-forming processes during the encounter.
Using scanning Fabry-Perot interferometry, we studied the contribution
of circular and non-circular motions and the response of the ionized
gas to external perturbations. We compared the kinematics with direct
images of the pair and traced the star-forming processes and
gravitational effects due to the presence of the other galaxy. The
spectral energy distribution of each member of the pair was fitted. A
mass model was fitted to the rotation curve of each galaxy.
Large, non-circular motions detected in both galaxies are associated
with a bar, spiral arms, and HII regions for the inner parts of the
galaxies, and with the tidal interaction for the outer parts of the
discs.
Bifurcations in the rotation curves indicate that the galaxies have
recently undergone their pericentric passage. The pattern speed of a
perturbation of one of the galaxies is computed. Location of a
possible corotation seems to indicate that the gravitational response
of the ionized gas in the outer parts of the disc is related to the
regions where ongoing star formation is confined. The spectral energy
distribution (SED) fit indicates a slightly different star formation
history for each member of the pair. For both galaxies, a
pseudo-isothermal halo better fits the global mass distribution.
Description:
Scanning Fabry-Perot interferometry of the redshifted Halpha emission
line of the luminous infrared galaxy pair NGC 5257/58 (Arp 240) The
FITS file contains the data cube with the first and second coordinates
corresponding to the (x,y) spatial coordinates of the image, and the
third coordinate corresponding to the wavelength. The data cube has
been reduced using the ADHOCw software and calibrated in wavelength.
The cube was taken using the PUMA scanning Fabry-Perot interferometer
at the 2.1m telescope in the Observatorio Astronomico Nacional in the
San Pedro Martir sierra in Mexico with a plate scale of 0.58"x0.58".
Average spatial resolution during observation was of 1.5"x1.5".
Spectral resolution of 19km/s per channel. The FoV equals 8.0'x7.8'.
Objects:
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RA (2000) DE Designation(s)
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13 39 55.2 +00 50 13 NGC 5257/58 = Arp 240
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 143 1 Information of FITS datacude
fits/* . 1 FITS datacube
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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- 8 F8.4 deg RAdeg Right Ascension of center (J2000)
9- 17 F9.6 deg DEdeg Declination of center (J2000)
19- 22 F4.2 arcsec/pix Scale Scale of the image
24- 26 I3 --- Nx [512] Number of pixels along X-axis
28- 30 I3 --- Ny [512] Number of pixels along Y-axis
32- 33 I2 --- Nz [48] Number of slides
35- 38 I4 km/s bVel [6765] Lower value of velocity interval
40- 43 I4 km/s BVel [7679] Upper value of velocity interval
45- 48 F4.1 km/s dVel [19.0] Velocity resolution
50- 54 I5 Kibyte size [49160] Size of FITS file
56- 61 A6 --- Mol Emission line (Halpha)
63- 78 A16 --- FileName Name of FITS file, in subdirectory fits
80-143 A64 --- Title Title of the FITS file
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Acknowledgements:
Staff at Observatorio Astronomico Nacional-San Pedro Martir (OAN-SPM)
Isaura Fuentes-Carrera, isaura.fuentescarrera(at)gmail.com
(End) Isaura Fuentes-Carrera [OAN-SPM], Patricia Vannier [CDS] 16-Nov-2018