J/A+A/659/A46 Halpha images of 6 lenticular galaxies (Boselli+, 2022)
A Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE).
XII. Ionised gas emission in the inner regions of lenticular galaxies.
Boselli A., Fossati M., Longobardi A., Kianfar K., Dametto N.Z., Amram P.,
Anderson J.P., Andreani P., Boissier S., Boquien M., Buat V., Consolandi G.,
Cortese L., Cote P., Cuillandre J.C., Ferrarese L., Galbany L., Gavazzi G.,
Gwyn S., Hensler G., Hutchings J., Peng E.W., Postma J., Roediger J.,
Roehlly Y., Serra P., Trinchieri G.
<Astron. Astrophys. 659, A46 (2022)>
=2022A&A...659A..46B 2022A&A...659A..46B (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Optical ; Ultraviolet ; Photometry, H-alpha
Keywords: galaxies: elliptical and lenticular, cD - galaxies: ISM -
galaxies: evolution - galaxies: interactions -
galaxies: clusters: general - galaxies: clusters: individual: Virgo
Abstract:
As part of the Virgo Cluster Survey Tracing Ionised Gas Emission, a
blind narrow-band Hα+[NII] imaging survey of the Virgo cluster
carried out with MegaCam at the CFHT, we discovered eight massive
(1010≲Mstar≲1011M☉) lenticular galaxies with prominent
ionised gas emission features in their inner (a few kiloparsec)
regions. These features are either ionised gas filaments similar to
those observed in cooling flows (two galaxies), or they are thin discs
with sizes 0.7≲R(Hα)≲2.0kpc (six galaxies), thus significantly
smaller than those of the stellar disc
(R(Hα)~=7-22%Riso(r)). The morphological properties of these
discs are similar to those of the dust seen in absorption in
high-resolution HST images. Using a unique set of multifrequency data,
including new or archival ASTROSAT/UVIT, GALEX, HST, CFHT, Spitzer,
and Herschel imaging data, combined with IFU (MUSE, ALMA) and
long-slit (SOAR) spectroscopy, we show that while the gas that is
located within these inner discs is photoionised by young stars, which
signals ongoing star formation, the gas in the filamentary structures
is shock ionised. The star formation surface brightness of these discs
is similar to that observed in late-type galaxies. Because of their
reduced size, however, these lenticular galaxies are located below the
main sequence of unperturbed or cluster star-forming systems. By
comparing the dust masses measured from absorption maps in optical
images, from the Balmer decrement, or estimated by fitting the
UV-to-far-IR spectral energy distribution of the target galaxies, we
confirm that the dust masses derived from optical attenuation maps are
heavily underestimated because of geometrical effects due to the
relative distribution of the absorbing dust and the emitting stars. We
also show that these galaxies have gas-to-dust ratios of
G/D≃8030320, and that the star formation within these discs
follows the Schmidt relation, but with an efficiency that is reduced
by a factor of ∼2.5. Using our unique set of multifrequency data, we
discuss the possible origin of the ionised gas in these objects, which
suggests multiple and complex formation scenarios for massive
lenticular galaxies in clusters.
Description:
Narrow-band (NB) Hα imaging observations were carried out during
the VESTIGE survey (Boselli et al., 2018A&A...614A..56B 2018A&A...614A..56B). The data
were obtained using MegaCam at the CFHT in the NB filter MP9603
(λc=6590Å; {DELTA}λ=104Å). Because of the redshift
of the galaxies, this filter includes the emission of the Balmer
Hα line and of the two [NII] lines (λ=6548,6583Å). `
Objects:
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RA (2000) DE Designation(s)
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12 19 30.58 +14 52 39.8 NGC 4262 = UGC 7365
12 27 26.50 +11 06 27.6 NGC 4429 = UGC 7568
12 29 00.03 +13 58 42.9 NGC 4459 = UGC 7614
12 29 28.00 +08 45 00.6 NGC 4469 = UGC 7622
12 29 59.08 +12 20 55.2 NGC 4476 = UGC 7637
12 34 03.03 +07 41 56.9 NGC 4526 = UGC 7718
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 156 9 List of fits images
fits/* . 9 Individual fits images
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See also:
J/A+A/646/A139 : IC 3476 Halpha image (Boselli+, 2021)
J/A+A/650/A99 : NGVS 3543 images at 8 wavelengths (Junais+, 2021)
J/A+A/659/A45 : NGC4330 GHASP and PUMA datacubes (Sardaneta+, 2022)
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- 24 F5.3 arcsec/pix scale ? Scale of the image
26- 29 I4 --- Nx Number of pixels along X-axis
31- 34 I4 --- Ny Number of pixels along Y-axis
36- 45 A10 "date" Obs.date Observation date
47- 51 I5 Kibyte size Size of FITS file
53- 75 A23 --- FileName Name of FITS file, in subdirectory fits
77-156 A80 --- Title Title of the FITS file
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Acknowledgements:
Alessandro Boselli, alessandro.boselli(at)lam.fr
References:
Boselli et al., Paper I 2018A&A...614A..56B 2018A&A...614A..56B
Fossati et al., Paper II 2018A&A...614A..57F 2018A&A...614A..57F
Boselli et al., Paper III 2018A&A...615A.114B 2018A&A...615A.114B
Boselli et al., Paper IV 2018A&A...620A.164B 2018A&A...620A.164B
Boselli et al., Paper V 2019A&A...623A..52B 2019A&A...623A..52B
Boselli et al., Paper VI 2020A&A...634L...1B 2020A&A...634L...1B
Longobardi et al., Paper VII 2020A&A...644A.161L 2020A&A...644A.161L
Volmer et al., Paper VIII 2021A&A...645A.121V 2021A&A...645A.121V
Boselli et al., Paper IX 2021A&A...646A.139B 2021A&A...646A.139B, Cat. J/A+A/646/A139
Junais et al., Paper X 2021A&A...650A..99J 2021A&A...650A..99J, Cat. J/A+A/650/A99`
Sardaneta et al., Paper XI 2022A&A...659A..45S 2022A&A...659A..45S, Cat. J/A+A/659/A45
(End) Patricia Vannier CDS 13-Nov-2021