The structure of early-type galaxies from the ACS Virgo and Fornax cluster surveys: cores, nuclei and supermassive black holes

AbstractThe core structure of early-type galaxies is revisited in light of recent results from the ACS Virgo and Fornax Cluster Surveys. These surveys are comprised of HST/ACS g, z band images for a representative sample of 143 early-type galaxies, spanning a factor 720 in B-band luminosity. The data indicates a clear transition in the core structure going from the brightest to the faintest galaxies. In contrast to previous claims, however, this transition is found to be a continuous function of galaxy magnitude. We characterize the core structure in terms of deviations of the observed surface brightness profile – measured within ~ 2% of the galaxy effective radius – relative to the inner extrapolation of the Sérsic law that best fits the profiles on larger scales. Virtually all galaxies fainter than MB ~ −20 mag contain distinct stellar nuclei, and are described by surface brightness profiles that lie above the Sérsic extrapolation, while the reverse is true for brighter galaxies. The latter are also known to host supermassive black holes. A relation between SBHs and stellar nuclei is suggested by the fact that both types of “central massive objects” contain the same fraction, 0.2% of the total mass of the host galaxy.

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The Fornax Deep Survey with the VST

Astronomy and Astrophysics ◽

10.1051/0004-6361/201833741 ◽

2019 ◽

Vol 623 ◽

pp. A1 ◽

Cited By ~ 16

Author(s):

E. Iodice ◽

M. Spavone ◽

M. Capaccioli ◽

R. F. Peletier ◽

G. van de Ven ◽

...

Keyword(s):

Globular Clusters ◽

Surface Brightness ◽

Major Axis ◽

Position Angle ◽

Early Type ◽

Semi Major Axis ◽

Cluster Galaxies ◽

The Galaxy ◽

Deep Survey ◽

Fornax Cluster

Context. This paper is based on the multi-band (ugri) Fornax Deep Survey (FDS) with the VLT Survey Telescope (VST). We study bright early-type galaxies (mB ≤ 15 mag) in the 9 square degrees around the core of the Fornax cluster, which covers the virial radius (Rvir ∼ 0.7 Mpc). Aims. The main goal of the present work is to provide an analysis of the light distribution for all galaxies out to unprecedented limits (in radius and surface brightness) and to release the main products resulting from this analysis in all FDS bands. We give an initial comprehensive view of the galaxy structure and evolution as a function of the cluster environment. Methods. From the isophote fit, we derived the azimuthally averaged surface brightness profiles, the position angle, and ellipticity profiles as a function of the semi-major axis. In each band, we derived the total magnitudes, effective radii, integrated colours, and stellar mass-to-light ratios. Results. The long integration times, the arcsec-level angular resolution of OmegaCam at VST, and the large covered area of FDS allow us to map the light and colour distributions out to large galactocentric distances (up to about 10−15 Re) and surface brightness levels beyond μr = 27 mag arcsec−2 (μB ≥ 28 mag arcsec−2). Therefore, the new FDS data allow us to explore in great detail the morphology and structure of cluster galaxies out to the region of the stellar halo. The analysis presented in this paper allows us to study how the structure of galaxies and the stellar population content vary with the distance from the cluster centre. In addition to the intra-cluster features detected in previous FDS works, we found a new faint filament between FCC 143 and FCC 147, suggesting an ongoing interaction. Conclusions. The observations suggest that the Fornax cluster is not completely relaxed inside the virial radius. The bulk of the gravitational interactions between galaxies happens in the W-NW core region of the cluster, where most of the bright early-type galaxies are located and where the intra-cluster baryons (diffuse light and globular clusters) are found. We suggest that the W-NW sub-clump of galaxies results from an infalling group onto the cluster, which has modified the structure of the galaxy outskirts (making asymmetric stellar halos) and has produced the intra-cluster baryons (ICL and GCs), concentrated in this region of the cluster.

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THE ACS FORNAX CLUSTER SURVEY. IV. DEPROJECTION OF THE SURFACE BRIGHTNESS PROFILES OF EARLY-TYPE GALAXIES IN THE VIRGO AND FORNAX CLUSTERS: INVESTIGATING THE “CORE/POWER-LAW DICHOTOMY”

The Astrophysical Journal ◽

10.1088/0004-637x/726/1/31 ◽

2010 ◽

Vol 726 (1) ◽

pp. 31 ◽

Cited By ~ 32

Author(s):

Lisa Glass ◽

Laura Ferrarese ◽

Patrick Côté ◽

Andrés Jordán ◽

Eric Peng ◽

...

Keyword(s):

Power Law ◽

Surface Brightness ◽

Early Type ◽

Cluster Survey ◽

The Core ◽

Fornax Cluster

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Black Hole Growth and Host Galaxy Morphology

Proceedings of the International Astronomical Union ◽

10.1017/s1743921310006964 ◽

2009 ◽

Vol 5 (S267) ◽

pp. 438-441

Author(s):

Kevin Schawinski ◽

C. Megan Urry ◽

Shanil Virani ◽

Paolo Coppi ◽

Steven P. Bamford ◽

...

Keyword(s):

Black Holes ◽

Black Hole ◽

Host Galaxy ◽

Early Type ◽

Black Hole Mass ◽

Local Universe ◽

Opposite Trend ◽

The Galaxy ◽

Black Hole Growth ◽

Hole Growth

AbstractWe use data from large surveys of the local universe (SDSS+Galaxy Zoo) to show that the galaxy–black hole connection is linked to host morphology at a fundamental level. The fraction of early-type galaxies with actively growing black holes, and therefore the AGN duty cycle, declines significantly with increasing black hole mass. Late-type galaxies exhibit the opposite trend: the fraction of actively growing black holes increases with black hole mass.

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The inner workings of early-type galaxies: cores, nuclei and supermassive black holes

Proceedings of the International Astronomical Union ◽

10.1017/s1743921307005108 ◽

2006 ◽

Vol 2 (S238) ◽

pp. 261-268 ◽

Cited By ~ 1

Author(s):

Laura Ferrarese ◽

Patrick Côté

Keyword(s):

Black Holes ◽

Virgo Cluster ◽

Supermassive Black Holes ◽

Early Type ◽

Cluster Survey ◽

The Core

AbstractRecent years have seen dramatic progress in the study of the core and nuclear properties of galaxies. The structure of the cores has been shown to vary methodically with global and nuclear properties, as cores respond to the mechanisms by which galaxies form/evolve. The dynamical centers of galaxies have been found capable of hosting two seemingly disparate objects: supermassive black holes (SBHs) and compact stellar nuclei. In a drastic departure from previous beliefs, it has been discovered that both structures are common: galaxies lacking SBHs and/or stellar nuclei are the exception, rather than the norm. This review explores the connection between cores, SBHs and stellar nuclei in early-type galaxies, as revealed by the ACS Virgo Cluster Survey.

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AGN feedback and star formation in ETGs: negative and positive feedback

Proceedings of the International Astronomical Union ◽

10.1017/s1743921316007535 ◽

2015 ◽

Vol 11 (S315) ◽

pp. 224-227 ◽

Cited By ~ 1

Author(s):

Luca Ciotti ◽

Jeremiah P. Ostriker ◽

Andrea Negri ◽

Silvia Pellegrini ◽

Silvia Posacki ◽

...

Keyword(s):

Black Holes ◽

Star Formation ◽

Stellar Population ◽

State Of The Art ◽

Host Galaxy ◽

Early Type ◽

Spatial And Temporal Scales ◽

Cooling Flows ◽

The Galaxy ◽

Hydrodynamical Simulations

AbstractAGN feedback from supermassive black holes (SMBHs) at the center of early type galaxies is commonly invoked as the explanation for the quenching of star formation in these systems. The situation is complicated by the significant amount of mass injected in the galaxy by the evolving stellar population over cosmological times. In absence of feedback, this mass would lead to unobserved galactic cooling flows, and to SMBHs two orders of magnitude more massive than observed. By using high-resolution 2D hydrodynamical simulations with radiative transport and star formation in state-of-the-art galaxy models, we show how the intermittent AGN feedback is highly structured on spatial and temporal scales, and how its effects are not only negative (shutting down the recurrent cooling episodes of the ISM), but also positive, inducing star formation in the inner regions of the host galaxy.

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Galaxy scaling relations from the ACS Virgo and Fornax Cluster Surveys: no evidence for a dwarf-giant dichotomy

Proceedings of the International Astronomical Union ◽

10.1017/s1743921308018218 ◽

2007 ◽

Vol 3 (S245) ◽

pp. 395-398 ◽

Cited By ~ 2

Author(s):

Patrick Côté ◽

Laura Ferrarese ◽

Andrés Jordán ◽

John P. Blakeslee ◽

Chin-Wei Chen ◽

...

Keyword(s):

Structural Properties ◽

Surface Brightness ◽

Local Group ◽

Absolute Magnitude ◽

Effective Radius ◽

Scaling Relations ◽

Early Type ◽

Central Surface ◽

Fornax Cluster

AbstractWe examine the photometric and structural properties of early-type galaxies derived from the ACS Virgo and Fornax Cluster Surveys, supplementing these data with previously published or newly reanalysed data for additional early-type galaxies in Virgo, Fornax and the Local Group. As we have noted elsewhere, Sérsic models are found to provide accurate representations of the observed brightness profiles on scales greater than a few percent of the effective radius, Re. On smaller scales, the brightness profiles of bright (MB ≳ −20) galaxies show central deficits with respect to the inward extrapolation of the Sérsic models; fainter galaxies usually show central excesses. Fainter than MB ≈ −20, we find a continuity in the photometric and structural scaling relations: i.e., between absolute magnitude, central surface brightness, Sérsic index, effective radius, and the surface brightness measured at, and averaged within, the effective radius. There is no evidence for a “dwarf/giant dichotomy” — a conclusion consistent with a number of recent studies but contrary to some earlier claims.

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Are we observing an NSC in course of formation in the NGC 4654 galaxy?

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab458 ◽

2021 ◽

Vol 503 (1) ◽

pp. 594-602

Author(s):

R Schiavi ◽

R Capuzzo-Dolcetta ◽

I Y Georgiev ◽

M Arca-Sedda ◽

A Mastrobuono-Battisti

Keyword(s):

Central Zone ◽

Effective Radius ◽

Host Galaxy ◽

Galactic Centre ◽

Future Evolution ◽

Orbital Parameters ◽

Relative Orbit ◽

The Future ◽

The Galaxy ◽

Massive Clusters

ABSTRACT We use direct N-body simulations to explore some possible scenarios for the future evolution of two massive clusters observed towards the centre of NGC 4654, a spiral galaxy with mass similar to that of the Milky Way. Using archival HST data, we obtain the photometric masses of the two clusters, M = 3 × 105 M⊙ and M = 1.7 × 106 M⊙, their half-light radii, Reff ∼ 4 pc and Reff ∼ 6 pc, and their projected distances from the photometric centre of the galaxy (both <22 pc). The knowledge of the structure and separation of these two clusters (∼24 pc) provides a unique view for studying the dynamics of a galactic central zone hosting massive clusters. Varying some of the unknown cluster orbital parameters, we carry out several N-body simulations showing that the future evolution of these clusters will inevitably result in their merger. We find that, mainly depending on the shape of their relative orbit, they will merge into the galactic centre in less than 82 Myr. In addition to the tidal interaction, a proper consideration of the dynamical friction braking would shorten the merging times up to few Myr. We also investigate the possibility to form a massive nuclear star cluster (NSC) in the centre of the galaxy by this process. Our analysis suggests that for low-eccentricity orbits, and relatively long merger times, the final merged cluster is spherical in shape, with an effective radius of few parsecs and a mass within the effective radius of the order of $10^5\, \mathrm{M_{\odot }}$. Because the central density of such a cluster is higher than that of the host galaxy, it is likely that this merger remnant could be the likely embryo of a future NSC.

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Upper limits on the mass of supermassive black holes from STIS archival data

Proceedings of the International Astronomical Union ◽

10.1017/s1743921308017730 ◽

2007 ◽

Vol 3 (S245) ◽

pp. 233-234

Author(s):

A. Beifiori ◽

E. M. Corsini ◽

E. Dalla Bontà ◽

A. Pizzella ◽

L. Coccato ◽

...

Keyword(s):

Black Holes ◽

Emission Line ◽

Supermassive Black Holes ◽

Archival Data ◽

Early Type ◽

Preliminary Results ◽

Upper Limits ◽

Nearby Galaxies ◽

Line Widths

AbstractThe growth of supermassive black holes (SMBHs) appears to be closely linked with the formation of spheroids. There is a pressing need to acquire better statistics on SMBH masses, since the existing samples are preferentially weighted toward early-type galaxies with very massive SMBHs. With this motivation we started a project aimed at measuring upper limits on the mass of the SMBHs that can be present in the center of all the nearby galaxies (D < 100 Mpc) for which STIS/G750M spectra are available in the HST archive. These upper limits will be derived by modeling the central emission-line widths ([N II] λλ6548, 6583, Hα and [S II] λλ6716, 6731) observed over an aperture of ~01 (R < 50 pc). Here we present our preliminary results for a subsample of 76 bulges.

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