Applying galactic archeology to massive galaxies using deep imaging surveys

AbstractVarious programs aimed at exploring the still largely unknown low surface brightness Universe with deep imaging optical surveys have recently started. They open a new window for studies of galaxy evolution, pushing the technique of galactic archeology outside the Local Group (LG). The method, based on the detection and analysis of the diffuse light emitted by collisional debris or extended stellar halos (rather than on stellar counts as done for LG systems), faces however a number of technical difficulties, like the contamination of the images by reflection halos and Galactic cirrus. I review here the on-going efforts to address them and highlight the preliminary promising results obtained with a systematic survey with MegaCam on the CFHT of nearby massive early-type galaxies done as part of the ATLAS3D, NGVS and MATLAS collaborations.

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Census and classification of low-surface-brightness structures in nearby early-type galaxies from the MATLAS survey

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa2248 ◽

2020 ◽

Vol 498 (2) ◽

pp. 2138-2166

Author(s):

Michal Bílek ◽

Pierre-Alain Duc ◽

Jean-Charles Cuillandre ◽

Stephen Gwyn ◽

Michele Cappellari ◽

...

Keyword(s):

Galaxy Evolution ◽

Surface Brightness ◽

Host Galaxy ◽

Early Type ◽

Limited Sample ◽

Visual Classification ◽

Star Forming ◽

Low Surface Brightness ◽

Model Predictions

ABSTRACT The morphology of galaxies gives essential constraints on the models of galaxy evolution. The morphology of the features in the low-surface-brightness (LSB) regions of galaxies has not been fully explored yet because of observational difficulties. Here we present the results of our visual inspections of very deep images of a large volume-limited sample of 177 nearby massive early-type galaxies from the MATLAS survey. The images reach a surface-brightness limit of 28.5–29 mag arcsec−2 in the g′ band. Using a dedicated navigation tool and questionnaire, we looked for structures at the outskirts of the galaxies such as tidal shells, streams, tails, disturbed outer isophotes, or peripheral star-forming discs, and simultaneously noted the presence of contaminating sources, such as Galactic cirrus. We also inspected internal substructures such as bars and dust lanes. We discuss the reliability of this visual classification investigating the variety of answers made by the participants. We present the incidence of these structures and the trends of the incidence with the mass of the host galaxy and the density of its environment. We find an incidence of shells, stream, and tails of approximately 15 per cent, about the same for each category. For galaxies with masses over 1011 M⊙, the incidence of shells and streams increases about 1.7 times. We also note a strong unexpected anticorrelation of the incidence of Galactic cirrus with the environment density of the target galaxy. Correlations with other properties of the galaxies, and comparisons to model predictions, will be presented in future papers.

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Stellar Populations of the Most Massive Galaxies

Proceedings of the International Astronomical Union ◽

10.1017/s1743921310007015 ◽

2009 ◽

Vol 5 (S267) ◽

pp. 459-459

Author(s):

Alexander Fritz ◽

Michael D. Hoenig ◽

Ricardo P. Schiavon

Keyword(s):

High Velocity ◽

Surface Brightness ◽

Stellar Populations ◽

Spectroscopic Properties ◽

Low Density ◽

Early Type ◽

Small Surface ◽

Fundamental Plane ◽

Massive Galaxies ◽

Bona Fide

Within the hierarchical CDM framework, gas-poor mergers contribute substantially to the building of the most massive galaxies (Faber et al. 2007). We want to test this scenario by studying the fundamental plane (FP) and the stellar populations of the most massive galaxies. We investigate a well-defined sample of massive early-type galaxies at 0.1<z<0.4, identified from the SDSS database. Out of 42,000 possible targets in the SDSS database, we extracted 23 luminous early-type galaxies with bona fide high velocity dispersions of σ>350 km s−1. These systems are located either in high or low-density environments and show a variety of small surface-brightness structure. Using archival HST/ACS images and Gemini/GMOS spectroscopy, we will explore the photometric and spectroscopic properties of these galaxies.

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LOFAR view of NGC 3998, a sputtering AGN

Astronomy and Astrophysics ◽

10.1051/0004-6361/201936796 ◽

2020 ◽

Vol 634 ◽

pp. A108 ◽

Cited By ~ 2

Author(s):

Sarrvesh S. Sridhar ◽

Raffaella Morganti ◽

Kristina Nyland ◽

Bradley S. Frank ◽

Jeremy Harwood ◽

...

Keyword(s):

Low Power ◽

Galaxy Evolution ◽

Spectral Index ◽

Surface Brightness ◽

Large Scale ◽

Radio Sources ◽

The Core ◽

Low Surface Brightness ◽

High Turbulence ◽

The Rich

Low-power radio sources dominate the radio sky. They tend to be small in size and dominated by their cores, but the origin of their properties and the evolution of their radio plasma are not well constrained. Interestingly, there is mounting evidence that low-power radio sources can significantly affect their surrounding gaseous medium and may therefore be more relevant for galaxy evolution than previously thought. In this paper, we present low radio frequency observations obtained with LOFAR at 147 MHz of the radio source hosted by NGC 3998. This is a rare example of a low-power source that is extremely dominated by its core, but that has two large-scale lobes of low surface brightness. We combine the new 147 MHz image with available 1400 MHz data to derive the spectral index over the source. Despite the low surface brightness, reminiscent of remnant structures, the lobes show an optically thin synchrotron spectral index (∼0.6). We interpret this as being due to rapid decollimation of the jets close to the core, to high turbulence of the plasma flow, and to entrainment of thermal gas. This could be the result of intermittent activity of the central active galactic nucleus, or, more likely, temporary disruption of the jet due to the interaction of the jet with the rich circumnuclear interstellar matter. Both would result in sputtering energy injection from the core, which would keep the lobes fed, albeit at a low rate. We discuss these results in connection with the properties of low-power radio sources in general. Our findings show that amorphous low surface brightness lobes should not be interpreted by default as remnant structures. Large deep surveys (in particular the LOFAR 150 MHz LoTSS and the recently started 1400 MHz Apertif survey) will identify a growing number of objects similar to NGC 3998 where these ideas can be further tested.

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Stellar systems in the direction of Pegasus I

Astronomy and Astrophysics ◽

10.1051/0004-6361/201834172 ◽

2018 ◽

Vol 620 ◽

pp. A166 ◽

Cited By ~ 2

Author(s):

Nélida M. González ◽

Analía V. Smith Castelli ◽

Favio R. Faifer ◽

Carlos G. Escudero ◽

Sergio A. Cellone

Keyword(s):

Local Group ◽

Structural Parameters ◽

Selection Effect ◽

Elliptical Galaxies ◽

Early Type ◽

Bias Effect ◽

Visual Identification ◽

Low Surface Brightness ◽

Large Systems ◽

Lsb Galaxies

Context. In spite of the numerous studies of low-luminosity galaxies in different environments, there is still no consensus about their formation scenario. In particular, a large number of galaxies displaying extremely low surface brightnesses have been detected in recent years and the nature of these objects is still under discussion. Aims. In order to enlarge the sample of known low-surface-brightness (LSB) galaxies and to try to provide clues about their nature, we report the detection of eight such objects ( μeff,g′≃ 27 mag arcsec−2) towards the group of galaxies Pegasus I. They are located, in projection, within a radius of ∼200 kpc in the very center of Pegasus I, close to the dominant elliptical galaxies NGC 7619 and NGC 7626. Methods. We analyzed deep, high-quality GEMINI-GMOS images with ELLIPSE within IRAF in order to obtain their brightness profiles and structural parameters. We also fit Sérsic functions to these profiles in order to compare their properties with those of typical early-type galaxies. Results. Assuming that these galaxies are at the distance of Pegasus I, we have found that their sizes are intermediate among similar objects reported in the literature. In particular, we found that three of these galaxies can be classified as ultra-diffuse galaxies and a fourth one displays a nucleus. The eight new LSB galaxies show significant color dispersion around the extrapolation towards faint luminosities of the color–magnitude relation defined by typical early-type galaxies. In addition, they display values of the Sérsic index below 1 (concave brightness profiles in linear scale), in agreement with values obtained for LSB galaxies in other environments. Conclusions. We show that there seems to be a bias effect in the size distributions of the detected LSBs in different environments, in the sense that more distant groups/clusters lack small r eff objects, while large systems are not found in the Local Group and nearby environments. While there may be an actual shortage of large LSB galaxies in low-density environments like the Local Group, the non-detection of small (and faint) systems at large distances is clearly a selection effect. As an example, LSB galaxies with similar sizes to those of the satellites of Andromeda in the Local Group will be certainly missed in a visual identification at the distance of Pegasus I.

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Galaxies in most dense environments at z ~ 1.4

Proceedings of the International Astronomical Union ◽

10.1017/s1743921314011491 ◽

2012 ◽

Vol 10 (H16) ◽

pp. 377-377

Author(s):

V. Strazzullo

Keyword(s):

Galaxy Evolution ◽

High Redshift ◽

Cosmic Time ◽

Cluster Center ◽

Final Conclusion ◽

Early Type ◽

Massive Galaxies ◽

Star Forming ◽

Cluster Cores ◽

Red Sequence

AbstractThe X-ray luminous system XMMU J2235-2557 at z~1.4 is among the most massive of the very distant galaxy clusters, and remains a unique laboratory to observe environment-biased galaxy evolution already 9 Gyr ago (Lidman et al.2008, Rosati et al.2009, Strazzullo et al.2010). At a cosmic time when cluster cores start showing evidence of a still active galaxy population, star-forming (M>1010M⊙) galaxies in XMMU J2235-2557 are typically located beyond ~250kpc from the cluster center, with the cluster core already effectively quenched and dominated by massive galaxies on a tight red sequence, showing early-type spectral features and bulge-dominated morphologies. While masses and stellar populations of these red-sequence galaxies suggest that they have largely completed their formation, their size is found to be typically smaller that similarly massive early-type galaxies in the local Universe, in agreement with many high-redshift studies. This would leave room for later evolution, likely through non-secular processes, changing their structure to match their local counterparts. On the other hand, uncertainties and biases in the determination of masses and sizes, as well as in the local mass-size relation, and the possible effect of progenitor bias, still hamper a final conclusion on the actual relevance of size evolution for early-type galaxies in this dense high-redshift environment.

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The Tully-Fisher relation for low surface brightness galaxies: implications for galaxy evolution

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/273.1.l35 ◽

1995 ◽

Vol 273 (1) ◽

pp. L35-L38 ◽

Cited By ~ 134

Author(s):

M. A. Zwaan ◽

J. M. van der Hulst ◽

W. J. G. de Blok ◽

S. S. McGaugh

Keyword(s):

Galaxy Evolution ◽

Surface Brightness ◽

Low Surface Brightness ◽

Fisher Relation ◽

Low Surface Brightness Galaxies

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The IAC stripe82 legacy project

Proceedings of the International Astronomical Union ◽

10.1017/s1743921316009005 ◽

2016 ◽

Vol 11 (S321) ◽

pp. 266-266

Author(s):

Javier Román ◽

Juergen Fliri ◽

Ignacio Trujillo

Keyword(s):

Surface Brightness ◽

Dwarf Galaxies ◽

Sloan Digital Sky Survey ◽

Diffuse Light ◽

Imaging Data ◽

Data Set ◽

Unique Possibility ◽

Sky Survey ◽

Low Surface Brightness

AbstractWe present new deep co-adds of data taken within Stripe 82 of the Sloan Digital Sky Survey (SDSS), especially stacked to reach the faintest surface brightness limits of this data set. Our reduction puts special emphasis on preserving the characteristics of the background (sky + diffuse light) in the input images using a non-aggressive sky subtraction strategy, resulting in an exquisite quality on extremely faint structures. The IAC Stripe 82 co-adds offer a rather unique possibility to study the low surface brightness Universe like stellar haloes and disc truncations, low surface brightness, tidal galactic interactions, extremely faint dwarf galaxies, intra-cluster light or diffuse light from galactic dust. The imaging data is publicly available at http://www.iac.es/proyecto/stripe82/.

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The haloes and environments of nearby galaxies (HERON) – II. The outer structure of edge-on galaxies

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa678 ◽

2020 ◽

Vol 494 (2) ◽

pp. 1751-1770 ◽

Cited By ~ 1

Author(s):

Aleksandr Mosenkov ◽

R Michael Rich ◽

Andreas Koch ◽

Noah Brosch ◽

David Thilker ◽

...

Keyword(s):

Surface Brightness ◽

3D Model ◽

Interacting Galaxies ◽

Deep Imaging ◽

Low Surface Brightness ◽

The Galaxy ◽

Nearby Galaxies

ABSTRACT The haloes and environments of nearby galaxies (HERON) project is aimed at studying haloes and low surface brightness (LSB) details near galaxies. In this second HERON paper, we consider in detail deep imaging (down to surface brightness of ∼28 mag arcsec−2 in the r band) for 35 galaxies, viewed edge-on. We confirm a range of LSB features previously described in the literature but also report new ones. We classify the observed outer shapes of the galaxies into three main types (and their prototypes): disc/diamond-like (NGC 891), oval (NGC 4302), and boxy (NGC 3628). We show that the shape of the outer disc in galaxies does not often follow the general 3D model of an exponential disc: 17 galaxies in our sample exhibit oval or even boxy isophotes at the periphery. Also, we show that the less flattened the outer disc, the more oval or boxy its structure. Many galaxies in our sample have an asymmetric outer structure. We propose that the observed diversity of the galaxy outer shapes is defined by the merger history and its intensity: if no recent multiple minor or single major merging took place, the outer shape is diamond-like or discy. On the contrary, interacting galaxies show oval outer shapes, whereas recent merging appears to transform the outer shape to boxy.

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A Flat Faint End of the Fornax Cluster Galaxy Luminosity Function

Proceedings of the International Astronomical Union ◽

10.1017/s1743921307014172 ◽

2007 ◽

Vol 3 (S244) ◽

pp. 331-335 ◽

Cited By ~ 1

Author(s):

S. Mieske ◽

M. Hilker ◽

L. Infante ◽

C. Mendes de Oliveira

Keyword(s):

Surface Brightness ◽

Luminosity Function ◽

Local Group ◽

Dwarf Galaxy ◽

High Mass ◽

Wide Field ◽

Early Type ◽

Cluster Galaxy ◽

Fornax Cluster ◽

Galaxy Luminosity Function

AbstractWe analyse the photometric properties of the early-type Fornax cluster dwarf galaxy population (MV > −17 mag), based on a wide field imaging study of the central cluster area in V and I band-passes with IMACS/Magellan at Las Campanas Observatory. We create a fiducial sample of ~ 100 Fornax cluster dwarf ellipticals (dEs) with −16.6 < MV < −8.8 mag in the following three steps: (1) To verify cluster membership, we measured I-band surface brightness fluctuations (SBF) distances to candidate dEs known from previous surveys; (2) We re-assessed morphological classifications for those candidate dEs that are too faint for SBF detection; and (3) We searched for new candidate dEs in the size-luminosity regime close to the resolution limit of previous surveys. The resulting fiducial dE sample follows a well-defined surface brightness – magnitude relation, showing that Fornax dEs are about 40% larger than Local Group dEs. The sample also defines a colour-magnitude relation similar to that of Local Group dEs. The early-type dwarf galaxy luminosity function in Fornax has a very flat faint end slope α ≃ −1.1 ± 0.1. We compare the number of dwarfs per unit mass with those in other environments and find that the Fornax cluster fits well into a general trend of a lack of high-mass dwarfs in more massive environments.

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