Eight New Milky Way Companions Discovered in First-Year Dark Energy Survey Data

Bechtol, K.; Drlica-Wagner, A.; Balbinot, E.; Pieres, A.; Simon, Joshua D.; Yanny, B.; Santiago, B.; Wechsler, Risa H.; Frieman, Joshua A.; Walker, A. R.; Williams, Paul; Rozo, Eduardo; Rykoff, E. S.; Queiroz, A. B. A.; Luque, E.; Benoit-Lévy, A.; Tucker, D. L.; Sevilla-Noarbe, I.; Gruendl, R. A.; Costa, L. N. da; Neto, A. Fausti; Maia, M. A. G.; Abbott, T. M. C.; Allam, S.; Armstrong, R.; Bauer, A.; Bernstein, G. M.; Bernstein, R. A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Rosell, A. Carnero; Castander, F. J.; Covarrubias, R.; D’Andrea, C. B.; DePoy, D. L.; Desai, S.; Diehl, H. T.; Eifler, T. F.; Estrada, J.; Evrard, A. E.; Fernández, E.; Finley, D. A.; Flaugher, B.; Gaztañaga, E.; Gerdes, D. W.; Girardi, L.; Gladders, Michael D.; Gruen, D.; Gutiérrez, G.; Hao, Jiangang; Honscheid, K.; Jain, Bhuvnesh; James, D. J.; Kent, Stephen M.; Krön, Richard G.; Kuêhn, K.; Kuropatkin, N.; Lahav, O.; Li, T. S.; Lin, Huan; Makler, M.; March, M.; Marshall, J. L.; Martini, Paul; Merritt, K. W.; Miller, Christopher J.; Miquel, R.; Mohr, J. J.; Neilsen, Eric H.; Nichol, R. C.; Nord, B.; Ogando, R. L. C.; Peoples, J.; Petravick, D.; Plazas, A. A.; Romer, A. K.; Roodman, A.; Šako, M.; Sánchez, E.; Scarpine, V.; Schubnell, M.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarlè, G.; Thaler, J. J.; Thomas, Daniel; Wester, W. C.; Zuntz, Joe

doi:10.1088/0004-637x/807/1/50

Cited by 556 publications

(590 citation statements)

References 91 publications

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“…This conclusion is supported by deeper imaging data from the Sloan Digital Sky Survey (SDSS, York et al 2000), Pan-STARRS (Kaiser et al 2010), and Dark Energy Survey (DES, Diehl et al 2014), which cover a significant portion of the northern and southern sky and are complete to beyond the host virial radius (i.e. > 300 kpc) at these stellar masses (Tollerud et al 2008;Koposov et al 2008;Laevens et al 2014;Koposov et al 2015;Bechtol et al 2015).…”

Section: Local Group Satellitesmentioning

confidence: 91%

Taking care of business in a flash : constraining the time-scale for low-mass satellite quenching with ELVIS

Fillingham

Cooper

Wheeler

et al. 2015

Mon. Not. R. Astron. Soc.

138

190

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The vast majority of dwarf satellites orbiting the Milky Way and M31 are quenched, while comparable galaxies in the field are gas-rich and star-forming. Assuming that this dichotomy is driven by environmental quenching, we use the ELVIS suite of N -body simulations to constrain the characteristic timescale upon which satellites must quench following infall into the virial volumes of their hosts. The high satellite quenched fraction observed in the Local Group demands an extremely short quenching timescale (∼ 2 Gyr) for dwarf satellites in the mass range M ∼ 10 6 − 10 8 M . This quenching timescale is significantly shorter than that required to explain the quenched fraction of more massive satellites (∼ 8 Gyr), both in the Local Group and in more massive host halos, suggesting a dramatic change in the dominant satellite quenching mechanism at M 10 8 M . Combining our work with the results of complementary analyses in the literature, we conclude that the suppression of star formation in massive satellites (M ∼ 10 8 − 10 11 M ) is broadly consistent with being driven by starvation, such that the satellite quenching timescale corresponds to the cold gas depletion time. Below a critical stellar mass scale of ∼ 10 8 M , however, the required quenching times are much shorter than the expected cold gas depletion times. Instead, quenching must act on a timescale comparable to the dynamical time of the host halo. We posit that ram-pressure stripping can naturally explain this behavior, with the critical mass (of M ∼ 10 8 M ) corresponding to halos with gravitational restoring forces that are too weak to overcome the drag force encountered when moving through an extended, hot circumgalactic medium.

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Section: Local Group Satellitesmentioning

confidence: 91%

Taking care of business in a flash : constraining the time-scale for low-mass satellite quenching with ELVIS

Fillingham

Cooper

Wheeler

et al. 2015

Mon. Not. R. Astron. Soc.

138

190

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“…This highly speculative suggestion is, however, important in the context of the recently discovered satellite galaxies potentially associated with the Magellanic Clouds (e.g. Bechtol et al 2015;Koposov et al 2015;Martin et al 2015). Figure 9 shows the CMD of NGC 121 including only sources within 3σ of the cluster proper motion (right).…”

Section: Ngc 121mentioning

confidence: 99%

The VMC survey

Cioni

Bekki

Girardi

et al. 2016

A&A

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Aims. In this study we use multi-epoch near-infrared observations from the VISTA survey of the Magellanic Cloud system (VMC) to measure the proper motions of different stellar populations in a tile of 1.5 deg 2 in size in the direction of the Galactic globular cluster 47 Tuc. We obtain the proper motion of the cluster itself, of the Small Magellanic Cloud (SMC), and of the field Milky Way stars. Methods. Stars of the three main stellar components are selected according to their spatial distributions and their distributions in colour−magnitude diagrams. Their average coordinate displacement is computed from the difference between multiple K s -band observations for stars as faint as K s = 19 mag. Proper motions are derived from the slope of the best-fitting line among ten VMC epochs over a time baseline of ∼1 yr. Background galaxies are used to calibrate the absolute astrometric reference frame. Results. The resulting absolute proper motion of 47 Tuc is (μ α cos(δ), μ δ ) = (+7.26 ± 0.03, −1.25 ± 0.03) mas yr −1 . This measurement refers to about 35 000 sources distributed between 10 and 60 from the cluster centre. For the SMC we obtain (μ α cos(δ), μ δ ) = (+1.16 ± 0.07, −0.81 ± 0.07) mas yr −1 from about 5250 red clump and red giant branch stars. The absolute proper motion of the Milky Way population in the line of sight (l = 305.9, b = −44.9) of this VISTA tile is (μ α cos(δ), μ δ ) = (+10.22 ± 0.14, −1.27 ± 0.12) mas yr −1 and has been calculated from about 4000 sources. Systematic uncertainties associated with the astrometric reference system are 0.18 mas yr −1 . Thanks to the proper motion we detect 47 Tuc stars beyond its tidal radius.

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“…The black line gives the result for the 11 classical satellites of the Milky Way, and the black dot is the estimation of Koposov et al (2008), which is based on the estimate of 45 MW satellites with MV < −5 and r < 280kpc from SDSS DR5. Recently more stellites of MW have been discovered by the Dark Energy Survey (DES; Bechtol et al 2015;Drlica-Wagner et al 2015;Koposov et al 2015), the VST-Atlas (Torrealba et al 2016) and Pan-STARRS 3π surveys (Laevens et al 2015a,b). Fig.11 of Bose et al (2017) has included these latest observed satellites, which is consistent with the data shown in our Fig.…”

Section: The Abundance Of Milky Way Satellitesmentioning

confidence: 99%

The galaxy population in cold and warm dark matter cosmologies

Wang

González-Pérez²,

Xie

et al. 2017

Monthly Notices of the Royal Astronomical Society

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We use a pair of high resolution N-body simulations implementing two dark matter models, namely the standard cold dark matter (CDM) cosmogony and a warm dark matter (WDM) alternative where the dark matter particle is a 1.5 keV thermal relic. We combine these simulations with the GALFORM semi-analytical galaxy formation model in order to explore differences between the resulting galaxy populations. We use GALFORM model variants for CDM and WDM that result in the same z = 0 galaxy stellar mass function by construction. We find that most of the studied galaxy properties have the same values in these two models, indicating that both dark matter scenarios match current observational data equally well. Even in under-dense regions, where discrepancies in structure formation between CDM and WDM are expected to be most pronounced, the galaxy properties are only slightly different. The only significant difference in the local universe we find is in the galaxy populations of "Local Volumes", regions of radius 1 to 8Mpc around simulated Milky Way analogues. In such regions our WDM model provides a better match to observed local galaxy number counts and is five times more likely than the CDM model to predict subregions within them that are as empty as the observed Local Void. Thus, a highly complete census of the Local Volume and future surveys of void regions could provide constraints on the nature of dark matter.

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Eight New Milky Way Companions Discovered in First-Year Dark Energy Survey Data

Cited by 556 publications

References 91 publications

Taking care of business in a flash : constraining the time-scale for low-mass satellite quenching with ELVIS

Taking care of business in a flash : constraining the time-scale for low-mass satellite quenching with ELVIS

The VMC survey

The galaxy population in cold and warm dark matter cosmologies

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