The extended halo of Centaurus A: uncovering satellites, streams, and substructures

Abstract

We present the widest-field resolved stellar map to date of the closest ($D\sim 3.8$ Mpc) massive elliptical galaxy NGC 5128 (Centaurus A; Cen A), extending out to a projected galactocentric radius of $\sim 150$ kpc. The dataset is part of our ongoing Panoramic Imaging Survey of Centaurus and Sculptor (PISCeS) utilizing the Magellan/Megacam imager. We resolve a population of old red giant branch stars down to $\sim 1.5$ mag below the tip of the red giant branch, reaching surface brightness limits as low as ${\mu }_{V,0}\sim 32$ mag arcsec${}^{-2}$. The resulting spatial stellar density map highlights a plethora of previously unknown streams, shells, and satellites, including the first tidally disrupting dwarf around Cen A (CenA-MM-Dw3), which underline its active accretion history. We report 13 previously unknown dwarf satellite candidates, of which 9 are confirmed to be at the distance of Cen A (the remaining 4 are not resolved into stars), with magnitudes in the range $M_V=-7.2$ to $-13.0$, central surface brightness values of ${\mu }_{V,0}=25.4-26.9$ mag arcsec${}^{-2}$, and half-light radii of $r_h=0.22-2.92$ kpc. These values are in line with Local Group dwarfs but also lie at the faint/diffuse end of their distribution; interestingly, CenA-MM-Dw3 has similar properties to the recently discovered ultra-diffuse galaxies in Virgo and Coma. Most of the new dwarfs are fainter than the previously known Cen A satellites. The newly discovered dwarfs and halo substructures are discussed in light of their stellar populations, and they are compared to those discovered by the PAndAS survey of M31.

21 pages, 17 figures; ApJ in press

References in corpus (40)

• The Dartmouth Stellar Evolution Database
• Too big to fail? The puzzling darkness of massive Milky Way subhaloes
• Cats and Dogs, Hair and A Hero: A Quintet of New Milky Way Companions
• The ACS Nearby Galaxy Survey Treasury
• Beasts of the Southern Wild: Discovery of nine Ultra Faint satellites in the vicinity of the Magellanic Clouds
• Forty-Seven Milky Way-Sized, Extremely Diffuse Galaxies in the Coma Cluster
• The Haunted Halos of Andromeda and Triangulum: A panorama of galaxy formation in action
• Tracing Galaxy Formation with Stellar Halos II: Relating Substructure in Phase- and Abundance-Space to Accretion Histories
• The Atlas3D project -- XXIX. The new look of early-type galaxies and surrounding fields disclosed by extremely deep optical images
• Detection of a 60 Degree-Long Dwarf Galaxy Debris Stream
• The Hubble flow around the CenA / M83 galaxy complex
• Halo Mass and Assembly History Exposed in the Faint Outskirts: the Stellar and Dark Matter Haloes of Illustris Galaxies
• Hydra II: a faint and compact Milky Way dwarf galaxy found in the Survey of the Magellanic Stellar History
• Two Planes of Satellites in the Centaurus A Group
• A New Faint Milky Way Satellite Discovered in the Pan-STARRS1 3 pi Survey
• Discovery of New Dwarf Galaxies in the M81 Group
• The discovery of seven extremely low surface brightness galaxies in the field of the nearby spiral galaxy M101
• A Hero's Dark Horse: Discovery of an Ultra-Faint Milky Way Satellite in Pegasus
• Global Properties of M31's Stellar Halo from the SPLASH Survey. I. Surface Brightness Profile
• The Nature and Origin of Substructure in the Outskirts of M31. I. Surveying the Stellar Content with HST/ACS
• Discovery of a cold stellar stream in the ATLAS DR1 data
• On feathers, bifurcations and shells: the dynamics of tidal streams across the mass scale
• Discovery of a close pair of faint dwarf galaxies in the halo of Centaurus A
• Stellar streams around the Magellanic Clouds
• A clear age-velocity dispersion correlation in Andromeda's stellar disk
• The Nature and Origin of Substructure in the Outskirts of M31 -- II. Detailed Star Formation Histories
• Photometric properties of Local Volume dwarf galaxies
• Discovery of a new faint dwarf galaxy associated with NGC 253
• The Kinematics and Dynamics of the Globular Clusters and the Planetary Nebulae of NGC 5128
• Serendipitous Discovery of a Thin Stellar Stream near the Galactic Bulge in the Pan-STARRS1 3Pi Survey
• A tidally disrupting dwarf galaxy in the halo of NGC 253
• A PAndAS view of M31 dwarf elliptical satellites: NGC147 and NGC185
• Star Formation and Stellar Mass Assembly in Dark Matter Halos: From Giants to Dwarfs
• Tracing the outer halo in a giant elliptical to 25 Reff
• Interstellar medium disruption in the Centaurus A group
• The Complex North Transition Region of Centaurus A: A Galactic Wind
• Satellite accretion in action: a tidally disrupting dwarf spheroidal around the nearby spiral galaxy NGC 253
• The Complex North Transition Region of Centaurus A: Radio Structure
• Blasting away a dwarf galaxy: The "tail" of ESO 324-G024
• Low-metallicity stellar halo populations as tracers of dark matter haloes

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