Searches for new Milky Way satellites from the first two years of data of the Subaru/Hyper Suprime-Cam survey: Discovery of Cetus III

Homma, Daisuke; Chiba, Masashi; Okamoto, Sakurako; Komiyama, Yutaka; Tanaka, Masayuki; Tanaka, Mikito; Ishigaki, Miho N.; Hayashi, Kohei; Arimoto, N.; Garmilla, José A.; Lupton, Robert H.; Strauss, Michael A.; Miyazaki, Satoshi; Wang, Shiang‐Yu; Murayama, Hitoshi

doi:10.1093/pasj/psx050

Cited by 80 publications

(46 citation statements)

References 67 publications

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“…Our prediction for the total number of MW satellites is consistent with several recent studies (Newton et al 2018;Jethwa et al 2018;Kim et al 2018;Nadler et al 2019b), and it is lower than the empirical estimate in Paper I, which was recognized to be inflated due to the assumption of an isotropic satellite distribution. This prediction will be tested by upcoming deep imaging surveys; indeed, HSC-SSP has already started to probe this population of distant, low-surface-brightness MW satellites by discovering three new ultra-faint satellite candidates in ∼ 676 deg 2 of imaging data (Homma et al 2016(Homma et al , 2018(Homma et al , 2019.…”

Section: Observed Satellitesmentioning

confidence: 98%

Milky Way Satellite Census. II. Galaxy–Halo Connection Constraints Including the Impact of the Large Magellanic Cloud

Nadler¹,

Wechsler²,

Bechtol³

et al. 2020

ApJ

149

229

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The population of Milky Way (MW) satellites contains the faintest known galaxies, and thus provides essential insight into galaxy formation and dark matter microphysics. Here, we combine a model of the galaxy-halo connection with newly derived observational selection functions based on searches for satellites in photometric surveys over nearly the entire high-Galactic-latitude sky. In particular, we use cosmological zoom-in simulations of MW-like halos that include realistic Large Magellanic Cloud (LMC) analogs to fit the position-dependent MW satellite luminosity function. We report decisive evidence for the statistical impact of the LMC on the MW satellite population due to an estimated 6.5 ± 1.5 observed LMC-associated satellites, consistent with the number of LMC satellites inferred from Gaia proper motion measurements, confirming the predictions of cold dark matter models for the existence of satellites within satellite halos. Moreover, we infer that the LMC fell into the MW within the last 2 Gyr at high confidence. Based on our detailed full-sky modeling, we find that the faintest observed satellites inhabit halos with peak virial masses below 2.2 × 10 8 M at 95% confidence, and we place the first robust constraints on the fraction of halos that host galaxies in this regime. We predict that the faintest detectable satellites occupy halos with peak virial masses above 10 6 M , highlighting the potential for powerful galaxy formation and dark matter constraints from future dwarf galaxy searches.

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Section: Observed Satellitesmentioning

confidence: 98%

Milky Way Satellite Census. II. Galaxy–Halo Connection Constraints Including the Impact of the Large Magellanic Cloud

Nadler¹,

Wechsler²,

Bechtol³

et al. 2020

ApJ

149

229

View full text Add to dashboard Cite

show abstract

“…[288]), Pan-STARRS (e.g., Ref. [289]), MagLiteS [290], HSC (Hyper Suprime-Cam; [291]), and VST ATLAS surveys [292]. Most of these new satellites have properties distinct from the those of the classical (pre-SDSS) satellites: they are tiny (M * 10 5 M ), ancient (consistent with being reionization fossils [293,294]), and extremely low in surface brightness.…”

Section: Cusp/core Problemmentioning

confidence: 99%

Gravitational probes of dark matter physics

2018

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The nature of dark matter is one of the most pressing questions in physics. Yet all our present knowledge of the dark sector to date comes from its gravitational interactions with astrophysical systems. Moreover, astronomical results still have immense potential to constrain the particle properties of dark matter in the near future. We introduce a simple 2D parameter space which classifies models in terms of a particle physics interaction strength and a characteristic astrophysical scale on which new physics appears, in order to facilitate communication between the fields of particle physics and astronomy. We survey the known astrophysical anomalies that are suggestive of non-trivial dark matter particle physics, and present a theoretical and observational program for future astrophysical measurements that will shed light on the nature of dark matter.

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“…Greco et al 2018b) and satellite galaxies in our Milky Way (e.g. Homma et al 2018), to study low surface brightness galaxies (e.g. Greco et al 2018a) and to investigate the stellar density profile of our Milky Way out to large distances (e.g.…”

Section: Introductionmentioning

confidence: 99%

The stellar halo of isolated central galaxies in the Hyper Suprime-Cam imaging survey

Wang

Han

Sonnenfeld

et al. 2019

Monthly Notices of the Royal Astronomical Society

Self Cite

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We study the faint stellar halo of isolated central galaxies, by stacking galaxy images in the HSC survey and accounting for the residual sky background sampled with random points. The surface brightness profiles in HSC r-band are measured for a wide range of galaxy stellar masses (9.2 < log 10 M * /M < 11.4) and out to 120 kpc. Failing to account for the stellar halo below the noise level of individual images will lead to underestimates of the total luminosity by 15%. Splitting galaxies according to the concentration parameter of their light distributions, we find that the surface brightness profiles of low concentration galaxies drop faster between 20 and 100 kpc than those of high concentration galaxies. Albeit the large galaxy-to-galaxy scatter, we find a strong self-similarity of the stellar halo profiles. They show unified forms once the projected distance is scaled by the halo virial radius. The colour of galaxies is redder in the centre and bluer outside, with high concentration galaxies having redder and more flattened colour profiles. There are indications of a colour minimum, beyond which the colour of the outer stellar halo turns red again. This colour minimum, however, is very sensitive to the completeness in masking satellite galaxies. We also examine the effect of the extended PSF in the measurement of the stellar halo, which is particularly important for low mass or low concentration galaxies. The PSF-corrected surface brightness profile can be measured down to ∼31 mag/arcsec 2 at 3-σ significance. PSF also slightly flattens the measured colour profiles.

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Searches for new Milky Way satellites from the first two years of data of the Subaru/Hyper Suprime-Cam survey: Discovery of Cetus III

Cited by 80 publications

References 67 publications

Milky Way Satellite Census. II. Galaxy–Halo Connection Constraints Including the Impact of the Large Magellanic Cloud

Milky Way Satellite Census. II. Galaxy–Halo Connection Constraints Including the Impact of the Large Magellanic Cloud

Gravitational probes of dark matter physics

The stellar halo of isolated central galaxies in the Hyper Suprime-Cam imaging survey

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