The Fornax Deep Survey with the VST. IV. A size and magnitude limited catalog of dwarf galaxies in the area of the Fornax cluster
University of Oulu1, Astronomical Observatory of Capodimonte2, European Southern Observatory3, Heidelberg University4, University of Naples Federico II5, INAF6, University of Turku7, Smithsonian Astrophysical Observatory8, Max Planck Society9, Kapteyn Astronomical Institute10, ASTRON11, University of La Laguna12, Spanish National Research Council13
TL;DR: The Fornax Deep Survey (FDS) dwarf galaxy catalog as discussed by the authors was used to study the galaxies down to r'-band magnitude m(r') approximate to 21 mag (M-r' approximate to -10.5 mag), which opens a new parameter regime to investigate the evolution of dwarf galaxies in the cluster environment.
Abstract: Context. The Fornax Deep Survey (FDS), an imaging survey in the u', g', r', and i'-bands, has a supreme resolution and image depth compared to the previous spatially complete Fornax Cluster Catalog (FCC). Our new data allows us to study the galaxies down to r'-band magnitude m(r') approximate to 21 mag (M-r' approximate to -10.5 mag), which opens a new parameter regime to investigate the evolution of dwarf galaxies in the cluster environment. After the Virgo cluster, Fornax is the second nearest galaxy cluster to us, and with its different mass and evolutionary state, it provides a valuable comparison that makes it possible to understand the various evolutionary effects on galaxies and galaxy clusters. These data provide an important legacy dataset to study the Fornax cluster. Aims. We aim to present the Fornax Deep Survey (FDS) dwarf galaxy catalog, focusing on explaining the data reduction and calibrations, assessing the quality of the data, and describing the methods used for defining the cluster memberships and first order morphological classifications for the catalog objects. We also describe the main scientific questions that will be addressed based on the catalog. This catalog will also be invaluable for future follow-up studies of the Fornax cluster dwarf galaxies. Methods. As a first step we used the SExtractor fine-tuned for dwarf galaxy detection, to find galaxies from the FDS data, covering a 26 deg(2) area of the main cluster up to its virial radius, and the area around the Fornax A substructure. We made 2D-decompositions of the identified galaxies using GALFIT, measure the aperture colors, and the basic morphological parameters like concentration and residual flux fraction. We used color-magnitude, luminosity-radius and luminosity-concentration relations to separate the cluster galaxies from the background galaxies. We then divided the cluster galaxies into early- and late-type galaxies according to their morphology and gave first order morphological classifications using a combination of visual and parametric classifications. Results. Our final catalog includes 14 095 galaxies. We classify 590 galaxies as being likely Fornax cluster galaxies, of which 564 are dwarfs (M-r' (') > -18.5 mag) consisting our Fornax dwarf catalog. Of the cluster dwarfs we classify 470 as early-types, and 94 as late-type galaxies. Our final catalog reaches its 50% completeness limit at magnitude M-r' = -10.5 mag and surface brightness (mu) over bar (e,r') = 26 mag arcsec(-2), which is approximately three magnitudes deeper than the FCC. Based on previous works and comparison with a spectroscopically confirmed subsample, we estimate that our final Fornax dwarf galaxy catalog has less than or similar to 10% contamination from the background objects.
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TL;DR: A comprehensive review of the evolution of galaxy structure in the universe from the first galaxies we can currently observe at z~6 down to galaxies we see in the local universe is presented in this paper.
Abstract: I present a comprehensive review of the evolution of galaxy structure in the universe from the first galaxies we can currently observe at z~6 down to galaxies we see in the local universe. I further address how these changes reveal galaxy formation processes that galaxy structural analyses can provide. This review is pedagogical and begins with a detailed discussion of the major methods in which galaxies are studied morphologically and structurally. This includes the well-established visual method; Sersic fitting to measure galaxy sizes and surface brightness profile shapes; non-parametric structural methods including the concentration (C), asymmetry (A), clumpiness (S) (CAS) method, as well as newer structural indices. Included is a discussion of how these structural indices measure fundamental properties of galaxies such as their scale, star formation rate, and ongoing merger activity. Extensive observational results are shown demonstrating how broad galaxy morphologies and structures change with time up to z~3, from small, compact and peculiar systems in the distant universe to the formation of the Hubble sequence we find today. This review further addresses how structural methods measure accurately the merger history out to z~3. The properties and evolution of bulges, disks, bars, and at z>1 large star forming clumps are also described, along with how morphological galaxy quenching occurs. Furthermore, the role of environment in producing structure in galaxies over cosmic time is treated. Alongside the evolution of general structure, I also delineate how galaxy sizes change with time, with measured sizes up to a factor of 2-5 smaller at high redshift at a given stellar mass. This review concludes with a discussion of how galaxy structure reveals the formation mechanisms behind galaxies, providing a new and unique way to test theories of galaxy formation.
85 citations
INAF1, Max Planck Society2, European Southern Observatory3, University of Padua4, University of Vienna5, Leiden University6, Spanish National Research Council7, University of La Laguna8, University of California, Santa Cruz9, Australian Astronomical Observatory10, Macquarie University11, University of Hertfordshire12
TL;DR: In this paper, a high-resolution map of the line-of-sight kinematics, line strengths of the stars, ionised gas reaching 2.3 R e for 21 early-type galaxies, and 1.2 R E for 10 late-type ones.
Abstract: The 31 brightest galaxies (m B ≤ 15 mag) inside the virial radius of the Fornax cluster were observed from the centres to the outskirts with the Multi Unit Spectroscopic Explorer on the Very Large Telescope. These observations provide detailed high-resolution maps of the line-of-sight kinematics, line strengths of the stars, ionised gas reaching 2–3 R e for 21 early-type galaxies, and 1–2 R e for 10 late-type galaxies. The majority of the galaxies are regular rotators, with eight hosting a kinematically distinct core. Only two galaxies are slow rotators. The mean age, total metallicity, and [Mg/Fe] abundance ratio in the bright central region inside 0.5 R e and in the galaxy outskirts are presented. Extended emission-line gas is detected in 13 galaxies, most of them are late-type objects with wide-spread star formation. The measured structural properties are analysed in relation to the galaxies’ position in the projected phase space of the cluster. This shows that the Fornax cluster appears to consist of three main groups of galaxies inside the virial radius: the old core; a clump of galaxies, which is aligned with the local large-scale structure and was accreted soon after the formation of the core; and a group of galaxies that fell in more recently.
57 citations
Cites background from "The Fornax Deep Survey with the VST..."
...The cluster hosts a vast population of dwarf and ultra compact galaxies (Munoz et al. 2015; Hilker 2015; Schulz et al. 2016; Venhola et al. 2017, 2018; Eigenthaler et al. 2018), an intra-cluster population of GCs (Schuberth et al. 2010; D’Abrusco et al. 2016; Cantiello et al. 2018; Pota et al.…...
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TL;DR: In this article, a catalog of 23,790 extended low-surface-brightness galaxies (LSBGs) identified in ~5000 deg2 from the first three years of imaging data from the Dark Energy Survey (DES) is presented.
Abstract: We present a catalog of 23,790 extended low-surface-brightness galaxies (LSBGs) identified in ~5000 deg2 from the first three years of imaging data from the Dark Energy Survey (DES) Based on a single-component Sersic model fit, we define extended LSBGs as galaxies with g-band effective radii Reff (g) > 2"5 and mean surface brightness μmeff (g )> 242 mag arcsec-2 We find that the distribution of LSBGs is strongly bimodal in (g-r) versus (g-i) color space We divide our sample into red (g-i≥060) and blue (g-i 15 kpc and central surface brightness μ0 (g )> 240 mag arcsec-2 The wide-area sample of LSBGs in DES can be used to test the role of environment on models of LSBG formation and evolution
57 citations
Cites methods from "The Fornax Deep Survey with the VST..."
...The Fornax Deep Survey (FDS) provides a catalog of 564 dwarf galaxies around Fornax, together with completeness estimates from simulations (Venhola et al. 2017, 2018)....
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TL;DR: In this paper, the authors used the multi-band Fornax Deep Survey (FDS) with the VLT Survey Telescope (VST) to explore the morphology and structure of cluster galaxies out to the stellar halo.
Abstract: 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 (m_B 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 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 GCs) 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.
55 citations
Cites background from "The Fornax Deep Survey with the VST..."
...The image quality of all FDS fields is presented by Venhola et al. (2018)....
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...…of NGC 1316 (Iodice et al. 2017b); iv) detected a previously unknown region of ICL in the core of the cluster, on the West side of NGC 1399 (Iodice et al. 2017a); v) provided a census of the low-surface brightness and dwarf galaxies in the whole area covered by FDS (Venhola et al. 2017, 2018)....
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...It hosts a vast population of dwarf galaxies and ultra compact galaxies (Munoz et al. 2015; Hilker 2015; Schulz et al. 2016; Venhola et al. 2017, 2018; Eigenthaler et al. 2018), an intra-cluster population of globular clusters (GCs) (Schuberth et al. 2008, 2010; D’Abrusco et al. 2016; Cantiello et…...
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TL;DR: The ADS abstract service at: http://adswww.harvard.edu has been updated considerably in the last year and new capabilities in the search engine include searching for multi-word phrases and searching for various logical combinations of search terms.
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TL;DR: Lee et al. as discussed by the authors measured the difference between the measured and predicted colors of a star, as derived from stellar parameters from the SEGUE Stellar Parameter Pipeline, and achieved uncertainties of 56, 34, 25, and 29 mmag in the colors u-g, g-r, r-i, and i-z, per star.
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3,896 citations
"The Fornax Deep Survey with the VST..." refers methods in this paper
...The fine tuning of the astrometric calibration is obtained by first associating the source lists extracted from the science images with the 2 Micron All-Sky Survey Point Source Catalog (2MASS PSC; Cutri et al. 2003) and fitting the residuals by a second order polynomial plane....
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