J/A+A/663/A12 Planetary nebulae in NGC3379 and NGC3384 (Hartke+, 2022)
The halo of M105 and its group environment as traced by planetary nebula
populations. II. Using kinematics of single stars to unveil the presence of
intragroup light around the Leo I galaxies NGC 3384 and M105.
Hartke J., Arnaboldi M., Gerhard O., Coccato L., Merrifield M., Kuijken K.,
Pulsoni C., Agnello A., Bhattacharya S., Spiniello C., Cortesi A.,
Freeman K.C., Napolitano N.R., Romanowsky A.J
<Astron. Astrophys. 663, A12 (2022)>
=2022A&A...663A..12H 2022A&A...663A..12H (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Planetary nebulae ; Photometry ; Optical
Keywords: galaxies: individual: M105 -
galaxies: elliptical and lenticular, cD -
galaxies: groups: individual: Leo I - galaxies: halos -
planetary nebulae: general
Abstract:
M105 (NGC 3379) is an early-type galaxy in the nearby Leo I group, the
closest galaxy group to contain all galaxy types and therefore an
excellent environment to explore the low-mass end of intra-group light
(IGL) assembly.
We present a new and extended kinematic survey of planetary nebulae
(PNe) in M105 and the surrounding 30'x30' in the Leo I group with the
Planetary Nebula Spectrograph (PN.S) to investigate kinematically
distinct populations of PNe in the halo and the surrounding IGL.
We use PNe as kinematic tracers of the diffuse stellar light in the
halo and IGL, and employ photo-kinematic Gaussian mixture models to
(i) separate contributions from the companion galaxy NGC 3384, and
(ii) associate PNe with structurally defined halo and IGL components
around M105. We present a catalogue of 314 PNe in the surveyed area
and firmly associate 93 of these with the companion galaxy NGC 3384
and 169 with M105. The PNe in M105 are further associated with its
halo (138) and the surrounding exponential envelope (31). We also
construct smooth velocity and velocity dispersion fields and calculate
projected rotation, velocity dispersion, and λR profiles for
the different components. PNe associated with the halo exhibit
declining velocity dispersion and rotation profiles as a function of
radius, while the velocity dispersion and rotation of the exponential
envelope increase notably at large radii. The rotation axes of these
different components are strongly misaligned.
Based on the kinematic profiles, we identify three regimes with
distinct kinematics that are also linked to distinct stellar
population properties: (i) the rotating core at the centre of the
galaxy (within 1∼Reff) formed in situ and is dominated by metal-rich
([M/H]∼0) stars that also likely formed in situ, (ii) the halo from 1
to 7.5Reff consisting of a mixture of intermediate-metallicity and
metal-rich stars ([M/H]>-1), either formed in situ or was brought in
via major mergers, and (iii) the exponential envelope reaching beyond
our farthest data point at 16 Reff, predominately composed of
metal-poor ([M/H]←1) stars. The high velocity dispersion and moderate
rotation of the latter are consistent with those measured for the
dwarf satellite galaxies in the Leo I group, indicating that this
exponential envelope traces the transition to the IGL.
Description:
photom.dat contains information about planetary nebula (PN) candidates
in the outer regions of the elliptical galaxy M105 in the Leo I group.
The catalogue is the result of a broad- and narrow-band imaging survey
with SuprimeCam at Subaru Telescope as described in Hartke et al.
(2020A&A...642A..46H 2020A&A...642A..46H). The catalogue only contains objects that are
brighter than the limiting magnitude [OIII]mag>25.6.
kinema.dat contains information about PNe in the outer regions of the
elliptical galaxy M105 in the Leo I group. The catalogue is the result
of a spectroscopic survey with the Planetary Nebula Spectrograph at
the William Herschel Telescope. The catalogue only contains PNe with
velocities within 3sigma about the robust mean.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
photom.dat 58 226 Planetary nebula candidates in the outer regions
of the elliptical galaxy M105 in the Leo I group
(table A1)
kinema.dat 112 319 Planetary nebulae in the outer regions of the
elliptical galaxy M105 in the Leo I group
(table A2)
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Byte-by-byte Description of file: photom.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- ID PN identifier, M105-SCAM-NNN
15- 16 I2 h RAh Right ascension (J2000)
18- 19 I2 min RAm Right ascension (J2000)
21- 27 F7.4 s RAs Right ascension (J2000)
29 A1 --- DE- Declination sign (J2000)
30- 31 I2 deg DEd Declination (J2000)
33- 34 I2 arcmin DEm Declination (J2000)
36- 42 F7.4 arcsec DEs Declination (J2000)
44- 50 F7.4 mag [OIII]mag Apparent AB magnitude in the [OIII] narrow
band (1)
52- 58 F7.4 mag Vmag Apparent AB magnitude in the V broad band
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Note (1): To convert AB magnitudes into 5007mag magnitudes from the [OIII] line,
the relation by Arnaboldi et al. (2003AJ....125..514A 2003AJ....125..514A) can be used, which is
5007mag = [OIII]mag + 2.49.
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Byte-by-byte Description of file: kinema.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 20 A20 --- ID PN identifier (1)
22- 23 I2 h RAh Right ascension (J2000)
25- 26 I2 min RAm Right ascension (J2000)
28- 34 F7.4 s RAs Right ascension (J2000)
36 A1 --- DE- Declination sigm (J2000)
37- 38 I2 deg DEd Declination (J2000)
40- 41 I2 arcmin DEm Declination (J2000)
43- 49 F7.4 arcsec DEs Declination (J2000)
51- 64 F14.10 mag [OIII]mag Apparent AB magnitude in the [OIII] narrow
band (2)
66- 75 F10.5 km/s Vlos Line-of-sight velocity
77- 89 F13.10 km/s e_Vlos Error on the line-of-sight velocity
91-112 F22.20 --- fM105 [0/1] Membership probability to belong to the
galaxy M105 (3)
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Note (1): Objects with IDs starting with M105-C and N3384 were observed first by
Douglas et al. (2007ApJ...664..257D 2007ApJ...664..257D, Cat. J/ApJ/664/257, PNS-EPN NGC3379 NNN
in Simnad) and Cortesi et al. (2013A&A...549A.115C 2013A&A...549A.115C, Cat. J/A+A/549/A115,
PNS-EPN NGC3384-NNN in Simbad), respectively.
Two concatenated IDs denote PNe that were observed in two fields.
Note (2): To convert AB magnitudes into 5007mag magnitudes from the [OIII] line,
the relation by Arnaboldi et al. (2003AJ....125..514A 2003AJ....125..514A) can be used, which is
5007mag = [OIII]mag + 2.49.
Note (3): The probability space is defined such that probabilities larger than
f_M105>0.5 denote PNe associated with the galaxy M105 and probabilities
smaller than f_M105<0.5 PNe associated with the companion galaxy NGC 3384.
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Acknowledgements:
Johanna Hartke, jhartke(at)eso.org
References:
Hartke et al., Paper I 2020A&A...642A..46H 2020A&A...642A..46H
(End) Patricia Vannier [CDS] 25-Mar-2022