Radio Galaxy Zoo Talk

Misalignment between cold gas and stellar components in early-type galaxies

  • mlpeck by mlpeck

    Cross-posted from GZ Talk:

    This one has both a GZ and RGZ connection. Posted on arxiv 2 Feb 2015 and according to the comment line accepted to MNRAS:

    Wong, O. Ivy, et al. 2015, "Misalignment between cold gas and stellar components in early-type galaxies."

    This describes a pilot radio study of 4 "blue ellipticals" from Schawinski's compilation.

    Posted

  • mlpeck by mlpeck in response to mlpeck's comment.

    This is just an aside, but for some reason I always find this amusing. Both this paper and the original "blue elliptical" paper by Schawinski et al. (http://adsabs.harvard.edu/abs/2009MNRAS.396..818S) describe a sample of 204 galaxies.

    So how many are in the actual catalog? There are 215, both in the version on VizieR and in the supplementary data table at MNRAS!

    Posted

  • JeanTate by JeanTate in response to mlpeck's comment.

    Very cool, and congratulations, Ivy! ๐Ÿ˜ƒ

    Misalignment between cold gas and stellar components in early-type galaxies

    By: O. Ivy Wong, K. Schawinski, G.I.G. Jรณzsa, C.M. Urry, C.J. Lintott, B.D. Simmons, S. Kaviraj, K.L. Masters

    Ref: arXiv:1501.07653

    Abstract:

    Recent work suggests blue ellipticals form in mergers and migrate quickly from the blue cloud of star-forming galaxies to the red sequence of passively evolving galaxies, perhaps as a result of black hole feedback. Such rapid reddening of stellar populations implies that large gas reservoirs in the pre-merger star-forming pair must be depleted on short time scales. Here we present pilot observations of atomic hydrogen gas in four blue early-type galaxies that reveal increasing spatial offsets between the gas reservoirs and the stellar components of the galaxies, with advancing post-starburst age. Emission line spectra show associated nuclear activity in two of the merged galaxies, and in one case radio lobes aligned with the displaced gas reservoir. These early results suggest that a kinetic process (possibly feedback from black hole activity) is driving the quick truncation of star formation in these systems, rather than a simple exhaustion of gas supply.

    Nice combo of optical and radio observations, as mlpeck mentions; I found the first para of Section 3.1 ("Radio observations") very interesting (Talk truly messes up the formatting):

    We performed imaging of the 1.4 GHz radio continuum and the atomic Hydrogen (Hi) emission of our pilot sample using the WSRT in the Netherlands between June and November 2012. As the WSRT is an east-west interferometer, our observations were divided into several epochs to optimise the uv-coverage. The single 20 MHz band is sampled over 1024 channels in the maxi-short baseline configuration in order to obtain a spectral resolution of 4 km sโˆ’1 spanning the range of 4000 km sโˆ’1.

    Posted

  • ivywong by ivywong scientist, admin

    Thanks @JeanTate & @mlpeck. ๐Ÿ˜ƒ

    @mlpeck: sample selection is tricky business ๐Ÿ˜‰ ...

    Posted

  • c_cld by c_cld

    Misalignment between cold gas and stellar components in early-type galaxies

    O. Ivy Wong, K. Schawinski,

    http://mnras.oxfordjournals.org/content/447/4/3311.full

    http://news.sciencemag.org/space/2015/02/black-holes-can-cause-galaxies-age-prematurely

    Galaxy J0836 1237660765911253059

    J0836SDSS J083601.50+301559.0

    enter image description here

    enter image description here

    Figure 5.
    Multicolour composite of the J0836+30 field (centred on J0836+30) where the background colour image is a multicolour composite of the five SDSS optical ugriz bands. North and east are aligned to the top and left of the image. The Hโ€‰I reservoir (cyan) is observed to be offset to the north-east of the galaxy and lies linearly between the two 1.4 GHz unresolved radio continuum lobes (magenta). The yellow ring in the bottom-left of the figure represents the beam of these pilot radio observations.

    Posted

  • ivywong by ivywong scientist, admin

    Thanks @C_cid for posting Fig 5 ๐Ÿ˜ƒ

    Posted