matlas – Page 9

1 January 20153 September 2019

The new look of early-type galaxies and surrounding fields disclosed by extremely deep optical images

Observing sequence of MATLAS observations (Duc et al., 2015)

Galactic archaeology based on star counts is instrumental to reconstruct the past mass assembly of Local Group galaxies. The development of new observing techniques and data reduction, coupled with the use of sensitive large field of view cameras, now allows us to pursue this technique in more distant galaxies exploiting their diffuse low surface brightness (LSB) light. As part of the ATLAS3D project, we have obtained with the MegaCam camera at the Canada-France-Hawaii Telescope extremely deep, multiband images of nearby early-type galaxies (ETGs).

1 December 201431 January 2019

Accretion-Inhibited Star Formation in the Warm Molecular Disk of the Green-valley Elliptical Galaxy NGC 3226?

HI emission superimposed on a deep optical image of the galaxy from MATLAS (Appleton et al., 2014)

We present archival Spitzer photometry and spectroscopy and Herschel photometry of the peculiar “Green Valley” elliptical galaxy NGC 3226. The galaxy, which contains a low-luminosity active galactic nucleus (AGN), forms a pair with NGC 3227 and is shown to lie in a complex web of stellar and H I filaments.

15 September 20143 September 2019

Group image release 1 (as part of Atlas3D)

A sample of 92 galaxies with available deep g and r images (all located outside the Virgo cluster) presented in the Atlas3D paper XXIX: Duc et al., 2014. Images were obtained as part of of a series of regular multi–semester PI and snapshot programs in the framework of the ATLAS3D project (serving as a pilot program for MATLAS). The galaxies presented in this image release were observed between 2010 and 2013.

5 August 20143 September 2019

Early-type galaxies as seen by SDSS and MegaCam (image release)

Each panel displays true color images obtained with MegaCam on the CFHT (Right: composite of g’+r’+i’ or g’+r’ observations), and for reference with the Sloan Digital Sky Survey (Top left: SDSS/DR8 image queried from the navigation tool Aladin @ CDS). Their field of view corresponds to 40 times the effective radius of the galaxy. A grey- scale g’-band version of the MegaCam image, with a field of view of about 57×57 arcmin, is displayed to the bottom right. To better identify the various objects in the field – galaxies, but also foreground stars and extended Galactic cirrus –, the composite g+r or g+r+i image has been superimposed in overburden areas. The white square delineates the area covered by the other sub-panels.

1 May 201431 January 2019

Identification of old tidal dwarfs near early-type galaxies from deep imaging and H I observations

Composite MegaCam images of the ETGs hosting TDG candidates (Duc et al., 2014)

It has recently been proposed that the dwarf spheroidal galaxies located in the Local Group discs of satellites (DoSs) may be tidal dwarf galaxies (TDGs) born in a major merger at least 5 Gyr ago. Whether TDGs can live that long is still poorly constrained by observations. As part of deep optical and H I surveys with the Canada-France-Hawaii Telescope (CFHT) MegaCam camera and Westerbork Synthesis Radio Telescope made within the ATLAS3D project, and follow-up spectroscopic observations with the Gemini-North telescope, we have discovered old TDG candidates around several early-type galaxies.

1 January 201431 January 2019

NGC 1266 as a Local Candidate for Rapid Cessation of Star Formation

g and r wide-field imaging of NGC 1266 taken as part of the MATLAS survey (Alatelo et al., 2014)

We present new Spectrographic Areal Unit for Research on Optical Nebulae (SAURON) integral-field spectroscopy and Swift Ultraviolet Optical Telescope (UVOT) observations of molecular outflow host galaxy NGC 1266 that indicate NGC 1266 has experienced a rapid cessation of star formation.

1 January 201331 January 2019

Discovery of a giant HI tail in the galaxy group HCG 44

H I contours overlaid on the g-band CFHT/MegaCam image (Serra et al., 2013)

We report the discovery of a giant HI tail in the intragroup medium of HCG 44 as part of the ATLAS^3D survey. The tail is ˜ 300 kpc long in projection and contains ˜ 5 × 10⁸ M_⊙ of HI. We detect no diffuse stellar light at the location of the tail down to ˜ 28.5 mag arcsec^{– 2} in g band.

28 February 201214 February 2019

Protected: MATLAS large program proposal

21 July 201131 January 2019

Elliptical galaxies much younger than previously thought? (CFHT press release)

A sample of elliptical galaxies from the MATLAS survey, all showing clear signs of a recent collision @ Duc/CEA/CFHT

The standard model for elliptical galaxies formation is challenged by a new result uncovered by an international team of astronomers from the Atlas3D collaboration. Team members from CNRS, CEA, CFHT, and the Observatoire de Lyon published in the scientific journal Monthly Notices of the Royal Astronomical Society the first results from their study on two elliptical galaxies exhibiting features characteristic of a fairly recent merging, suggesting they are five times younger than commonly thought.