A Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE). XII. Ionised gas emission in the inner regions of lenticular galaxies

Autor(en)

A. Boselli, M. Fossati, A. Longobardi, K. Kianfar, N. Z. Dametto, P. Amram, J. P. Anderson, P. Andreani, S. Boissier, M. Boquien, V. Buat, G. Consolandi, L. Cortese, P. Côté, J. C. Cuillandre, L. Ferrarese, L. Galbany, G. Gavazzi, S. Gwyn, G. Hensler, J. Hutchings, E. W. Peng, J. Postma, J. Roediger, Y. Roehlly, P. Serra, G. Trinchieri

Abstrakt

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 ≲ M_star ≲ 10¹¹ M_⊙) 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)≲2.0 kpc (six galaxies), thus significantly smaller than those of the stellar disc (R(Hα)≃7 − 22%R_iso(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.

The reduced images are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/659/A46

Based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-French-Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France and the University of Hawaii. Based on observations collected at the European Southern Observatory under ESO programmes 097.D-0408 and 099.B-0384. Based in part on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia e Inovações (MCTI/LNA) do Brasil, the US National Science Foundation, NOIRLab, the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

Aix-Marseille Université, Università degli Studi di Milano-Bicocca, Instituto Tecnológico de Aeronáutica, Universidad de Antofagasta, European Organisation for Astronomical Research in the Southern Hemisphere (ESO), European Southern Observatory (Germany), University of Western Australia, ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), National Research Council Canada (NRC-CNRC), Université Paris Saclay, Institut d'Estudis Espacials de Catalunya (IEEC), Spanish National Research Council (CSIC), Peking University, University of Calgary, Osservatorio Astronomico di Cagliari INAF-OAC - Selargius, INAF Osservatorio Astronomico di Brera

Journal

Astronomy and Astrophysics

Band

659

ISSN

0004-6361

DOI

https://doi.org/10.1051/0004-6361/202142482

Publikationsdatum

03-2022

Peer-reviewed

Ja

ÖFOS 2012

103003 Astronomie, 103004 Astrophysik

Schlagwörter

ASJC Scopus Sachgebiete

Astronomy and Astrophysics, Space and Planetary Science

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/41b8f41e-9886-4a0a-b960-fa06b91d72ef