English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We study the properties of massive galaxies at an average redshift of z~0.34through stacking more than 42000 images of Luminous Red Galaxies from the SloanDigital Sky Survey. This is the largest dataset ever used for such an analysisand it allows us to explore the outskirts of massive red galaxies atunprecedented physical scales. Our image stacks extend farther than 400 kpc,where the r-band profile surface brightness reaches 30 mag arcsec-2. Thisanalysis confirms that the stellar bodies of luminous red galaxies follow asimple Sersic profile out to 100 kpc. At larger radii the profiles deviate fromthe best-fit Sersic models and exhibit extra light in the g, r, i and z-bandstacks. This excess light can probably be attributed to unresolved intragroupor intracluster light or a change in the light profile itself. We further showthat standard analyses of SDSS-depth images typically miss 20% of the totalstellar light and underestimate the size of LRGs by 10% compared to our bestfit r-band Sersic model of n=5.5 and r_e=13.1 kpc. If the excess light at r>100kpc is considered to be part of the galaxy, the best fit r-band Sersicparameters are n=5.8 and r_e=13.6 kpc. In addition we study the radiallydependent stack ellipticity and find an increase with radius from e=0.25 atr=10 kpc to e=0.3 at r=100 kpc. This provides support that the stellar lightthat we trace out to at least 100 kpc is physically associated with thegalaxies themselves and may confirm that the halos of individual LRGs havehigher ellipticities than their central parts. Lastly we show that thebroadband color gradients of the stacked images are flat beyond roughly 40 kpc,suggesting that the stellar populations do not vary significantly with radiusin the outer parts of massive ellipticals.

The faint stellar halos of massive red galaxies from stacks of more than 42000 SDSS LRG images