TY  - JOUR
A1  - Gong, Chen Chris
A1  - Libeskind, Noam I.
A1  - Tempel, Elmo
A1  - Guo, Quan
A1  - Gottloeber, Stefan
A1  - Yepes, Gustavo
A1  - Wang, Peng
A1  - Sorce, Jenny
A1  - Pawlowski, Marcel
T1  - The origin of lopsided satellite galaxy distribution in galaxy pairs
JF  - Monthly notices of the Royal Astronomical Society
N2  - It is well known that satellite galaxies are not isotropically distributed among their host galaxies as suggested by most interpretations of the Λ cold dark matter (ΛCDM) model. One type of anisotropy recently detected in the Sloan Digital Sky Survey (and seen when examining the distribution of satellites in the Local Group and in the Centaurus group) is a tendency to be so-called lopsided. Namely, in pairs of galaxies (like Andromeda and the Milky Way) the satellites are more likely to inhabit the region in between the pair, rather than on opposing sides. Although recent studies found a similar set-up when comparing pairs of galaxies in ΛCDM simulations indicating that such a set-up is not inconsistent with ΛCDM, the origin has yet to be explained. Here we examine the origin of such lopsided set-ups by first identifying such distributions in pairs of galaxies in numerical cosmological simulations, and then tracking back the orbital trajectories of satellites (which at z = 0 display the effect). We report two main results: first, the lopsided distribution was stronger in the past and weakens towards z = 0. Secondly, the weakening of the signal is due to the interaction of satellite galaxies with the pair. Finally, we show that the z = 0 signal is driven primarily by satellites that are on first approach, who have yet to experience a ‘flyby’. This suggests that the signal seen in the observations is also dominated by dynamically young accretion events.
KW  - galaxies: evolution
KW  - galaxies: formation
KW  - galaxy: kinematics and dynamics
KW  - Local Group
KW  - dark matter
KW  - cosmology: theory
Y1  - 2019
U6  - https://doi.org/10.1093/mnras/stz1917
SN  - 0035-8711
SN  - 1365-2966
VL  - 488
IS  - 3
SP  - 3100
EP  - 3108
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Zaritsky, Dennis
A1  - Courtois, Helene
A1  - Munoz-Mateos, Juan-Carlos
A1  - Sorce, Jenny
A1  - Erroz-Ferrer, S.
A1  - Comeron, S.
A1  - Gadotti, D. A.
A1  - Gil De Paz, A.
A1  - Hinz, J. L.
A1  - Laurikainen, E.
A1  - Kim, T.
A1  - Laine, J.
A1  - Menendez-Delmestre, K.
A1  - Mizusawa, T.
A1  - Regan, M. W.
A1  - Salo, H.
A1  - Seibert, M.
A1  - Sheth, K.
A1  - Athanassoula, E.
A1  - Bosma, A.
A1  - Cisternas, M.
A1  - Ho, Luis C.
A1  - Holwerda, B.
T1  - The baryonic Tully-Fisher relationship for S(4)G galaxies and the  "condensed" baryon fraction of galaxies
JF  - The astronomical journal
N2  - We combine data from the Spitzer Survey for Stellar Structure in Galaxies, a recently calibrated empirical stellar mass estimator from Eskew et al., and an extensive database of Hi spectral line profiles to examine the baryonic Tully-Fisher (BTF) relation. We find (1) that the BTF has lower scatter than the classic Tully-Fisher (TF) relation and is better described as a linear relationship, confirming similar previous results, (2) that the inclusion of a radial scale in the BTF decreases the scatter but only modestly, as seen previously for the TF relation, and (3) that the slope of the BTF, which we find to be 3.5 +/- 0.2 (Delta log M-baryon/Delta log v(c)), implies that on average a nearly constant fraction (similar to 0.4) of all baryons expected to be in a halo are "condensed" onto the central region of rotationally supported galaxies. The condensed baryon fraction, M-baryon/M-total, is, to our measurement precision, nearly independent of galaxy circular velocity (our sample spans circular velocities, vc, between 60 and 250 km s(-1), but is extended to v(c) similar to 10 km s(-1) using data from the literature). The observed galaxy-to-galaxy scatter in this fraction is generally <= a factor of 2 despite fairly liberal selection criteria. These results imply that cooling and heating processes, such as cold versus hot accretion, mass loss due to stellar winds, and active galactic nucleus driven feedback, to the degree that they affect the global galactic properties involved in the BTF, are independent of halo mass for galaxies with 10 < v(c) < 250 km s(-1) and typically introduce no more than a factor of two range in the resulting M-baryon/M-total. Recent simulations by Aumer et al. of a small sample of disk galaxies are in excellent agreement with our data, suggesting that current simulations are capable of reproducing the global properties of individual disk galaxies. More detailed comparison to models using the BTF holds great promise, but awaits improved determinations of the stellar masses.
KW  - galaxies: evolution
KW  - galaxies: formation
KW  - galaxies: fundamental parameters
KW  - galaxies: stellar content
KW  - galaxies: structure
Y1  - 2014
U6  - https://doi.org/10.1088/0004-6256/147/6/134
SN  - 0004-6256
SN  - 1538-3881
VL  - 147
IS  - 6
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  -