J/A+A/610/A14 ASASSN-15lh MUSE host spectroscopy (Kruehler+, 2018)
The supermassive black hole coincident with the luminous transient ASASSN-15lh
Kruehler T., Fraser M., Leloudas G., Schulze S., Stone N.C., van Velzen S.,
Amorin R., Hjorth J., Jonker P.G., Kann D.A., Kim S., Kuncarayakti H.,
Mehner A., Nicuesa Guelbenzu A.
<Astron. Astrophys. 610, A14 (2018)>
=2018A&A...610A..14K 2018A&A...610A..14K (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Supernovae
Keywords: stars: individual: ASASSN-15lh - galaxies: supermassive black holes
Abstract:
The progenitors of astronomical transients are linked to a specific
stellar population and galactic environment, and observing their host
galaxies hence constrains the physical nature of the transient itself.
Here, we use imaging from the Hubble Space Telescope, and spatially
resolved, medium-resolution spectroscopy from the Very Large Telescope
obtained with X-shooter and MUSE to study the host of the very
luminous transient ASASSN-15lh. The dominant stellar population at the
transient site is old (around 1 to 2Gyr) without signs of recent star
formation. We also detect emission from ionized gas, originating from
three different, time invariable, narrow components of collisionally
excited metal and Balmer lines. The ratios of emission lines in the
Baldwin-Phillips-Terlevich diagnostic diagram indicate that the
ionization source is a weak active galactic nucleus with a black hole
mass of MBH=5-3+8x108M☉, derived through the M*-σ
relation. The narrow line components show spatial and velocity offsets
on scales of 1kpc and 500km/s, respectively; these offsets are best
explained by gas kinematics in the narrow-line region. The location of
the central component, which we argue is also the position of the
supermassive black hole, aligns with that of the transient within an
uncertainty of 170pc. Using this positional coincidence as well as
other similarities with the hosts of tidal disruption events, we
strengthen the argument that the transient emission observed as
ASASSN-15lh is related to the disruption of a star around a
supermassive black hole, most probably spinning with a Kerr parameter
aBH≥0.5.
Description:
The two data files with fits extension (ASASSN-15lhastphotcube_2016.fits
and ASASSN-15lhastphotcube_2017.fits) are three-dimensional fits files
with a primary header and two extensions:
The primary header contains only the fits headers.
The first fits extensions (DATA) contain the observed flux values in
units of 10E-20erg/cm2/s/Å.
The dimensions of the cubes are 330x325x3681 for the 2016 data, and
317x323x3681 for the 2017 data, respectively.
The first two dimensions are celestial coordinates (RA, DEC), and the
last one the wavelength coordinate in Angstrom.
The second fits extensions (STAT) contain the estimated variance in
units of 10E-40erg-2cm-4s-2Å-2.
Objects:
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RA (2000) DE Designation(s)
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22 02 15.45 -61 39 34.6 ASASSN -15lh = SN 2015L
-------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 129 2 List of fits datacubes
fits/* . 2 Individual datacubes
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See also:
J/ApJ/828/3 : Swift obs. of the superluminous SNI ASASSN-15lh (Brown+, 2016)
Byte-by-byte Description of file: list.dat
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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- 43 I7 Kibyte size Size of FITS file
45- 78 A34 --- FileName Name of FITS file, in subdirectory fits
80-129 A50 --- Title Title of the FITS file
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Acknowledgements:
Thomas Kruehler, t.kruehler(at)gmail.com
(End) Patricia Vannier [CDS] 30-Oct-2017