A Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE). VIII. Modeling ram pressure stripping of diffuse gas in the Virgo cluster spiral galaxy NGC 4330
B. Vollmer, M. Fossati, A. Boselli, M. Soida, S. Gwyn, J. C. Cuillandre, Ph. Amram, S. Boissier, M. Boquien, G. Hensler
NGC 4330 is one of the Virgo galaxies whose UV distribution shows a tail structure. An associated tail structure is also observed in the HI and H$α$ emission distributions. Previous dynamical modeling showed that the galaxy is approaching the cluster center and is therefore undergoing increasing ram pressure stripping. Recent stellar population fitting of deep optical spectra together with multiband photometry lead to the determination of the time when star formation was quenched in the galactic disk. We introduce a new version of the dynamical model that includes the diffuse ionized gas and aim to reproduce the HI, H$α$, UV distributions together with the star formation histories of the outer gas-free parts of the galactic disk. The results of 50 simulations with five different Lorentzian temporal ram-pressure profiles and five different delays between the simulation onset and peak ram pressure are presented. The inclusion of diffuse gas stripping changes significantly the HI, UV, and H$α$ emission distributions. The simulations with diffuse gas stripping naturally lead to vertical low surface density filaments in the downwind region of the galactic disk. These filaments occur less frequently in the simulations without diffuse gas stripping. The simulations with diffuse gas stripping lead to better joint fits to the SEDs and optical spectra. The HI, NUV, and H$α$ morphologies of the model snapshots which best reproduce the SEDs and optical spectra are sufficiently different to permit a selection of best-fit models. We conclude that the inclusion of diffuse gas stripping significantly improves the resemblance between the model and observations. Our preferred model yields a time to peak ram pressure of 140 Myr in the future. The spatial coincidence of the radio continuum and diffuse H$α$ tails suggests that both gas phases are stripped together.
We have observed the giant elliptical galaxy M87 during the Virgo Environmental Survey Tracing Galaxy Evolution (VESTIGE), a blind narrow-band Halpha+[NII] imaging survey of the Virgo cluster carried out with MegaCam at the Canada French Hawaii Telescope (CFHT). The deep narrow-band image confirmed the presence of a filament of ionised gas extending up to ~ 3 kpc in the north-western direction and ~ 8 kpc to the south-east, with a couple of plumes of ionised gas, the weakest of which, at ~ 18 kpc from the nucleus, was previously unknown. The analysis of deep optical images taken from the NGVS …
The Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE) is a blind narrow-band Halpha+[NII] imaging survey of the Virgo cluster carried out with MegaCam at the Canada-French-Hawaii telescope (CFHT). We use a new set of data extracted from VESTIGE to study the impact of the hostile cluster environment on the star formation process down to the scale of HII regions (~ 50 pc). HII regions are identified and their parameters measured using the HIIphot code on a sample of 114 late-type galaxies spanning a wide range in morphological type (Sa-Sd, Im, BCD), stellar mass (10^6.5 <= M_star…
As part of the VESTIGE survey, a blind narrow-band Ha+[NII] imaging survey of the Virgo cluster carried out with MegaCam at the CFHT, we discovered 8 massive lenticular galaxies with prominent ionised gas emission features in their inner (few kpc) regions. These features are either ionised gas filaments similar to those observed in cooling flows (2 gal), or thin discs with sizes 0.7<R(Ha)<2.0 kpc (6 gal), thus significantly smaller than those of the stellar disc. These discs have morphological properties similar to those of the dust seen in absorption in high-resolution HST images. Using a uni…
We have observed the late-type peculiar galaxy NGC 4424 during VESTIGE, a blind narrow-band Halpha[NII] imaging survey of the Virgo cluster carried out with MegaCam at the CFHT. The presence of a 110 kpc long HI tail in the S direction indicates that this galaxy is undergoing a ram pressure stripping event. The deep narrow-band image revealed the presence of a low surface brightness ionised gas tail ~10 kpc long extending from the centre of the galaxy to the NW direction, in the direction opposite to the HI tail. Chandra and XMM X-rays data do not show any compact source in the nucleus nor the…
During pilot observations of the Virgo Environmental Survey Tracing Galaxy Evolution (VESTIGE), a blind narrow-band Halpha+[NII] imaging survey of the Virgo cluster carried out with MegaCam at the CFHT, we have observed the spiral galaxy NGC 4254 (M99). Deep Halpha+[NII] narrow-band and GALEX UV images revealed the presence of 60 compact (70-500 pc radius) star forming regions up to ~ 20 kpc outside the optical disc of the galaxy. These regions are located along a tail of HI gas stripped from the disc of the galaxy after a rapid gravitational encounter with another Virgo cluster member that si…
The Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE) is a blind narrow-band Halpha+[NII] imaging survey carried out with MegaCam at the Canada-France-Hawaii Telescope. The survey covers the whole Virgo cluster region from its core to one virial radius (104 deg^2). The sensitivity of the survey is of f(Halpha) ~ 4 x 10^-17 erg sec-1 cm^-2 (5 sigma detection limit) for point sources and Sigma (Halpha) ~ 2 x 10^-18 erg sec^-1 cm^-2 arcsec^-2 (1 sigma detection limit at 3 arcsec resolution) for extended sources, making VESTIGE the deepest and largest blind narrow-band survey of a …
The Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE) is a blind narrow-band H$α$+[NII] imaging survey carried out with MegaCam at the CFHT. During pilot observations we have observed NGC 4330, an intermediate mass, edge-on star forming spiral currently falling into the core of the Virgo cluster. New deep observations revealed a low surface brightness 10 kpc tail exhibiting a peculiar filamentary structure. The filaments are remarkably parallel one another and clearly indicate the direction of motion of the galaxy in the Virgo potential. Motivated by the detection of these feat…
We study the IB(s)m galaxy IC 3476 observed in the context of VESTIGE, a blind narrow-band Halpha+[NII] imaging survey of the Virgo cluster. The deep narrow-band (NB) image reveals a very pertubed ionised gas distribution, characterised by a prominent banana-shaped structure in the front of the galaxy formed of giant HII regions crossing the stellar disc, with star forming structures at ~8 kpc from the edges of the stellar disc, detected also in a deep FUV ASTROSAT/UVIT image. This particular morphology indicates that the galaxy is undergoing an almost edge-on ram pressure stripping event. The…
Using the VESTIGE survey, a deep narrow-band H$α$ imaging survey of the Virgo cluster carried on at the CFHT with MegaCam, we discovered a long diffuse tail of ionised gas in the edge-on late-type galaxy NGC 4330. This peculiar feature witnesses an ongoing ram pressure stripping (RPS) event able to remove the gas in the outer disc region. Tuned hydrodynamic simulations suggest that the RPS event is occurring almost face-on, making NGC 4330 the ideal candidate to study the effects of the perturbation in the direction perpendicular to the disc plane. We present here two new independent sets of F…
We measure FIR emission from tails of stripped dust following the ionised and atomic gas components in galaxies undergoing ram pressure stripping. We study the dust-to-gas relative distribution and mass ratio in the stripped interstellar medium and relate them to those of the intra-cluster medium, thus linking the cluster-ICM-galaxy evolution at small-scales. The galaxy sample consists of three Scd Virgo galaxies with stellar masses in the range $10^9\lesssim \mathrm{M_{*}} \lesssim 10^{10}\, \mathrm{M_{\odot}}$, and within 1 Mpc from the cluster centre, namely NGC 4330, NGC 4522, and NGC 4654…
The evolution of galaxies depends on their interaction with the surrounding environment. Ultra-diffuse galaxies (UDGs) have been found in large numbers in clusters. We detected a few star-forming blobs in the VESTIGE survey, located at $\sim$5 kpc from a UDG, namely NGVS 3543, in association with an HI gas cloud AGC 226178, suggesting a recent interaction between this low-surface-brightness system and the surrounding cluster environment. We use a complete set of multi-frequency data including deep optical, UV, and narrow-band H$α$ imaging and HI data to understand the formation process that ga…
A Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE). XIX. The discovery of a spectacular 230 kpc Halpha tail following NGC 4569 in the Virgo cluster
Low-surface-brightness galaxies (LSBs) contribute to a significant fraction of all the galaxies in the Universe. Ultra-diffuse galaxies (UDGs) form a subclass of LSBs that has attracted a lot of attention in recent years (although its definition may vary between studies). Although UDGs are found in large numbers in galaxy clusters, groups, and in the field, their formation and evolution are still very much debated. Using a comprehensive set of multiwavelength data from the NGVS (optical), VESTIGE (H$α$ narrowband), and GUViCS (UV) surveys, we studied a sample of 64 diffuse galaxies and UDGs in…
A Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE): XVI. The ubiquity of truncated star-forming disks across the Virgo cluster environment
Using a compilation of Halpha fluxes for 384 star forming galaxies detected during the VESTIGE survey, we study several important scaling relations for a complete sample of galaxies in a rich environment. The extraordinary sensitivity of the data allows us to sample the whole dynamic range of the Halpha luminosity function, from massive (M*~10^11 Mo) to dwarf systems (M*~10^6 Mo). This extends previous works to a dynamic range in stellar mass and star formation rate (10^-4<SFR<10 Mo yr^-1) never explored so far. The main sequence (MS) relation derived for all star forming galaxies within one v…
A Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE) XX. Star formation in the tidal tail of NGC 4254
Aix Marseille Univ, CNRS, CNES, LAM（艾克斯马赛大学）；INAF - Osservatorio Astronomico di Cagliari（意大利国家天体物理研究所卡利亚里天文台）；Como Lake Center for Astrophysiscs, DiSAT, Università degli Studi dell’Insubria（因苏布里亚大学）；INAF - Osservatorio Astronomico di Bologna（意大利国家天体物理研究所博洛尼亚天文台）；European Southern Observatory（欧洲南方天文台）；INAF - Osservatorio Astronomico di Capodimonte（意大利国家天体物理研究所卡波迪蒙特天文台）；Laboratoire de Physique de l’Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Observatoire de Paris（巴黎高等师范学院）；Department of Astrophysics, University of Vienna（维也纳大学）；Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange（蔚蓝海岸大学）；Università di Milano-Bicocca（米兰比可卡大学）
A Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE) XVIII. Reconstructing the star formation history of early-type galaxies through the combination of their UV and H$α$ emission
High ionisation lines in the soft X-ray band are generally associated to either interstellar hot gas along the line of sight or to photoionised gas intrinsic to the source. In the low-mass X-ray binary 4U 1820-30, the nature of these lines is not well understood. We characterised the ionised gas present along the line of sight towards the source producing the X-ray absorption lines of Mg XI, Ne IX, Fe XVII, O VII, and O VIII. We analysed all the observations available for this source in the XMM-Newton and Chandra archives, taken with the RGS, HETG, and LETG spectrometers. The high-resolution g…
The active galaxy MCG--6-30-15 has a 400 pc diameter stellar kinematically distinct core, counter-rotating with respect to the main body of the galaxy. Our previous high spatial resolution (0".1) H-band observations of this galaxy mapped the stellar kinematics and [Fe II] 1.64 μm gas dynamics though mainly restricted to the spatial region of the counter-rotating core. In this work we probe the stellar kinematics on a larger field-of-view and determine the ionised and molecular gas dynamics to study the formation of the counter-rotating core and the implications for AGN fuelling. We present int…
