J/A+A/621/A83 NGC 1566 ALMA and Gemini-GMOS/IFU datacubes (Slater+, 2019)
Outflows in the inner kiloparsec of NGC 1566 as revealed by molecular (ALMA)
and ionized gas (Gemini-GMOS/IFU) kinematics.
Slater R., Nagar N.M., Schnorr-Mueller A., Storchi-Bergmann T., Finlez C.,
Lena D., Ramakrishnan V., Mundell C.G., Riffel R.A., Peterson B.,
Robinson A., Orellana G.
<Astron. Astrophys. 621, A83 (2019)>
=2019A&A...621A..83S 2019A&A...621A..83S (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, Seyfert ; Galaxies, spectra; Galaxies, nearby;
Spectroscopy; Carbon monoxide ; Optical
Keywords: galaxies: nuclei - galaxies: active -
galaxies: kinematics and dynamics - galaxies: Seyfert
Abstract:
Tracing nuclear inflows and outflows in AGNs, determining the mass of
gas involved in them, and their impact on the host galaxy and nuclear
black hole requires 3-D imaging studies of both the ionized and
molecular gas. We map the distribution and kinematics of molecular and
ionized gas in a sample of active galaxies to quantify the nuclear
inflows and outflows. Here, we analyze the nuclear kinematics of NGC
1566 via ALMA observations of the CO J:2-1 emission at 24pc spatial
and ∼2.6km/s spectral resolution, and Gemini-GMOS/IFU observations
of ionized gas emission lines and stellar absorption lines at similar
spatial resolution, and 123km/s of intrinsic spectral resolution. The
morphology and kinematics of stellar, molecular (CO), and ionized
([NII]) emission lines are compared to the expectations from rotation,
outflows, and streaming inflows. While both ionized and molecular gas
show rotation signatures, there are significant non-circular motions
in the innermost 200pc and along spiral arms in the central kpc (CO).
The nucleus shows a double-peaked CO profile (full width at zero
intensity of 200km/s), and prominent (∼80km/s) blue- and redshifted
lobes are found along the minor axis in the inner arcseconds.
Perturbations by the large-scale bar can qualitatively explain all
features in the observed velocity field. We thus favor the presence of
a molecular outflow in the disk with true velocities of ∼180km/s in
the nucleus and decelerating to 0 by ∼72pc. The implied molecular
outflow rate is 5.6M☉/yr, with this gas accumulating in the
nuclear 2" arms. The ionized gas kinematics support an interpretation
of a similar but more spherical outflow in the inner 100pc, with no
signs of deceleration. There is some evidence of streaming inflows of
∼50km/s along specific spiral arms, and the estimated molecular mass
inflow rate, ∼0.1M☉/yr, is significantly higher than the SMBH
accretion rate (dM/dt=4.8x10-5M☉/yr).
Description:
Reduced datacubes obtained through ALMA and Gemini-GMOS/IFU
observations for the nuclear kiloparsec region of the nearby active
galaxy NGC 1566. ALMA observations were taken on June 29, 2014, during
Cycle 2: project- ID 2012.1.00474.S, using the ALMA Band 6 receivers
on thirty-two 12-meter antennas. We present the molecular gas emission
line of CO J:2-1 (observed frequency=229.401922GHz) at relatively high
channel spacing (∼1.3km/s), and systemic velocity subtracted
(1482km/s). This cube was calibrated and imaged using CASA 4.2.1.,
made with Brigg's weighting equivalent to a 'natural weighting', and a
synthesized beam of 0.6"x0.5" (beam PA=15.6°). The r.m.s. noise
per channel in line free channels is ∼1.2mJy/beam, and rises by up to
a factor 4 in channels with significant line emission.
Gemini-GMOS observations of NGC 1566 were obtained on the night of
27th of September 2011 in Integral Field Unit (IFU) mode and using the
R400_G5325 grating in combination with the r_G0326 filter (program ID:
GS-2011B-Q-23). This grating yielded an intrinsic spectral resolution
(FWHM) of 123km/s, which was sampled on the CCD at ∼30km/s per
pixel near the [NII] line. The total spectral coverage was from
5620Å to 6970Å. The observations consisted of two adjacent IFU
fields covering 7"x5" each, resulting in a total spatial coverage of
7x10 arcsec. Six exposures of 350 seconds were obtained for each
field, each slightly shifted in wavelength and position in order to
correct for detector defects and fill in CCD chip gaps. The data was
processed using specific tasks developed for GMOS data in the
gemini.gmos IRAF package (http://iraf.noao.edu)
Objects:
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RA (2000) DE Designation(s)
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04 20 00.42 -54 56 16.11 NGC 1566 = ESO 157-20
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
gen.dat 126 1 General quantities of NGC 1566 obtained
kin.dat 37 1 Relevant kinematic quantities of NGC 1566 obtained
list.dat 198 2 List of fits datacubes
fits/* . 2 Individual datacubes
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Byte-by-byte Description of file: gen.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right ascension of center (J2000.0)
11- 20 F10.5 deg DEdeg Declination of center (J2000.0)
22- 25 I4 km/s Vsys Systemic velocity of center by CO J:2-1
27- 36 F10.6 GHz COfreq CO J:2-1 frequency observed in the center
38- 41 F4.1 deg PA Position angle in the inner kiloparsec
43- 44 I2 deg Incl Inclination in the inner kiloparsec
46- 49 E4.1 Msun Mdisk Disk mass estimated from the inner CO J:2-1
rotation curve
51- 54 E4.1 Msun Mdisks Disk mass estimated from the inner stellar
rotation curve
56- 61 E6.2 Msun TMgas Total molecular gas mass in the inner 12" region
63- 68 E6.2 Msun e_TMgas Mean error on total molecular gas mass
70- 75 E6.2 Msun NMout Nuclear molecular outflow mass in the inner
0.4" region
77- 82 E6.2 Msun e_NMout Mean error on nuclear molecular outflow mass
84- 89 E6.2 Msun TMout Total molecular outflow mass in the inner
3" region
91- 96 E6.2 Msun e_TMout Mean error on total molecular outflow mass
98-103 E6.2 Msun BHmass Central black hole mass
105-110 E6.2 Msun e_BHmass Mean error on the central black hole mass
112-118 E7.2 W Lbol Bolometric luminosity of the AGN
120-126 E7.2 W e_Lbol Mean error on the bolometric luminosity of
the AGN
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Byte-by-byte Description of file: kin.dat
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Bytes Format Units Label Explanations
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1- 2 I2 km/s sigCO Nuclear velocity dispersion of CO J:2-1
in the inner 1" region
4- 6 I3 km/s sigNII Nuclear velocity dispersion of [NII]
in the inner 1" region
8- 12 F5.1 km/s vmax Maximum rotational velocity of CO J:2-1
in the inner 6" region
14- 19 F6.2 km/s vmaxs Maximum stellar rotational velocity
in the inner 6" region
21- 23 I3 km/s vout Nuclear maximum outflow velocity of CO
J:2-1 in the inner 3" region and
along the plane of the disk
25- 27 I3 km/s sigs Central mean stellar velocity dispersion
in the inner 12" region
29 I1 km/s e_sigs Mean error of central stellar velocity
dispersion
31- 33 F3.1 Msun/yr Outrate Nuclear molecular outflow rate
in the inner 0.4" region
35- 37 F3.1 Msun/yr Infrate Nuclear molecular inflow rate potentially
inflowing to the inner 6" region
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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- 22 I3 --- Nx Number of pixels along X-axis
24- 26 I3 --- Ny Number of pixels along Y-axis
28- 31 I4 --- Nz Number of pixels along Z-axis
33- 55 A23 "datime" Obs.Date Observation date (YYYY/MM/DDThh:mm:ss.sss)
57- 62 F6.2 GHz bFreq ? Lower value of frequency interval
64- 70 F7.3 GHz BFreq ? Upper value of frequency interval
72- 79 F8.1 Hz dFreq ? Frequency resolution
81- 85 I5 Kibyte size Size of FITS file
87- 99 A13 --- FileName Name of FITS file, in subdirectory fits
101-198 A98 --- Title Title of the FITS file
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Acknowledgements:
Roy Slater, royslater(at)astro-udec.cl
(End) Roy Slater [Univ. Concepcion], Patricia Vannier [CDS] 03-Dec-2018