Quantifying the connection between galaxies and their host dark matter halos has been key for testing cosmological models on various scales. Below
Using mass–radius composition models, small planets (
- NSF-PAR ID:
- 10495608
- Publisher / Repository:
- DOI PREFIX: 10.3847
- Date Published:
- Journal Name:
- The Planetary Science Journal
- Volume:
- 5
- Issue:
- 3
- ISSN:
- 2632-3338
- Format(s):
- Medium: X Size: Article No. 71
- Size(s):
- ["Article No. 71"]
- Sponsoring Org:
- National Science Foundation
More Like this
-
Abstract M ⋆∼ 109M ⊙, such studies have primarily relied on the satellite galaxy population orbiting the Milky Way (MW). Here we present new constraints on the connection between satellite galaxies and their host dark matter subhalos using the largest sample of satellite galaxies in the Local Volume (D ≲ 12 Mpc) to date. We use 250 confirmed and 71 candidate dwarf satellites around 27 MW-like hosts from the Exploration of Local VolumE Satellites (ELVES) Survey and use the semianalyticalSatGen model for predicting the population of dark matter subhalos expected in the same volume. Through a Bayesian model comparison of the observed and the forward-modeled satellite stellar mass functions (SSMFs), we infer the satellite stellar-to-halo mass relation. We find that the observed SSMF is best reproduced when subhalos at the low-mass end are populated by a relation of the form , with a moderate slope of and a low scatter, constant as a function of the peak halo mass, of . A model with a steeper slope (α grow= 2.39 ± 0.06) and a scatter that grows with decreasingM peakis also consistent with the observed SSMF but is not required. Our new model for the satellite–subhalo connection, based on hundreds of Local Volume satellite galaxies, is in line with what was previously derived using only MW satellites. -
Abstract The cluster mass–richness relation (MRR) is an observationally efficient and potentially powerful cosmological tool for constraining the matter density Ωmand the amplitude of fluctuations
σ 8using the cluster abundance technique. We derive the MRR relation usingGalWCat19 , a publicly available galaxy cluster catalog we created from the Sloan Digital Sky Survey-DR13 spectroscopic data set. In the MRR, cluster mass scales with richness as . We find that the MRR we derive is consistent with both the IllustrisTNG and mini-Uchuu cosmological numerical simulations, with a slope ofβ ≈ 1. We use the MRR we derived to estimate cluster masses from theGalWCat19 catalog, which we then use to set constraints on Ωmandσ 8. Utilizing the all-member MRR, we obtain constraints of Ωm= andσ 8= , and utilizing the red member MRR only, we obtain Ωm= andσ 8= . Our constraints on Ωmandσ 8are consistent and very competitive with the Planck 2018 results. -
Abstract We measure the metallicities of 374 red giant branch (RGB) stars in the isolated, quenched dwarf galaxy Tucana using Hubble Space Telescope narrowband (F395N) calcium H and K imaging. Our sample is a factor of ∼7 larger than what is available from previous studies. Our main findings are as follows. (i) A global metallicity distribution function (MDF) with
and . (ii) A metallicity gradient of −0.54 ± 0.07 dex (−2.1 ± 0.3 dex kpc−1) over the extent of our imaging (∼2.5R e ), which is steeper than literature measurements. Our finding is consistent with predicted gradients from the publicly available FIRE-2 simulations, in which bursty star formation creates stellar population gradients and dark matter cores. (iii) Tucana’s bifurcated RGB has distinct metallicities: a blue RGB with and and a red RGB with and . (iv) At fixed stellar mass, Tucana is more metal-rich than Milky Way satellites by ∼0.4 dex, but its blue RGB is chemically comparable to the satellites. Tucana’s MDF appears consistent with star-forming isolated dwarfs, though MDFs of the latter are not as well populated. (v) About 2% of Tucana’s stars have [Fe/H] < −3% and 20% have [Fe/H] > −1. We provide a catalog for community spectroscopic follow-up. -
Abstract We report the discovery of two transiting planets around the bright (
V = 9.9 mag) main-sequence F7 star TOI-1670 by the Transiting Exoplanet Survey Satellite. TOI-1670 b is a sub-Neptune (R ⊕) on a 10.9 day orbit, and TOI-1670 c is a warm Jupiter (R Jup) on a 40.7 day orbit. Using radial velocity observations gathered with the Tull Coudé Spectrograph on the Harlan J. Smith telescope and HARPS-N on the Telescopio Nazionale Galileo, we find a planet mass ofM Jupfor the outer warm Jupiter, implying a mean density of g cm−3. The inner sub-Neptune is undetected in our radial velocity data (M b< 0.13M Jupat the 99% confidence level). Multiplanet systems like TOI-1670 hosting an outer warm Jupiter on a nearly circular orbit ( ) and one or more inner coplanar planets are more consistent with “gentle” formation mechanisms such as disk migration or in situ formation rather than high-eccentricity migration. Of the 11 known systems with a warm Jupiter and a smaller inner companion, eight (73%) are near a low-order mean-motion resonance, which can be a signature of migration. TOI-1670 joins two other systems (27% of this subsample) with period commensurabilities greater than 3, a common feature of in situ formation or halted inward migration. TOI-1670 and the handful of similar systems support a diversity of formation pathways for warm Jupiters. -
Abstract We present new measurements of cosmic microwave background (CMB) lensing over 9400 deg2of the sky. These lensing measurements are derived from the Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) CMB data set, which consists of five seasons of ACT CMB temperature and polarization observations. We determine the amplitude of the CMB lensing power spectrum at 2.3% precision (43
σ significance) using a novel pipeline that minimizes sensitivity to foregrounds and to noise properties. To ensure that our results are robust, we analyze an extensive set of null tests, consistency tests, and systematic error estimates and employ a blinded analysis framework. Our CMB lensing power spectrum measurement provides constraints on the amplitude of cosmic structure that do not depend on Planck or galaxy survey data, thus giving independent information about large-scale structure growth and potential tensions in structure measurements. The baseline spectrum is well fit by a lensing amplitude ofA lens= 1.013 ± 0.023 relative to the Planck 2018 CMB power spectra best-fit ΛCDM model andA lens= 1.005 ± 0.023 relative to the ACT DR4 + WMAP best-fit model. From our lensing power spectrum measurement, we derive constraints on the parameter combination of from ACT DR6 CMB lensing alone and when combining ACT DR6 and PlanckNPIPE CMB lensing power spectra. These results are in excellent agreement with ΛCDM model constraints from Planck or ACT DR4 + WMAP CMB power spectrum measurements. Our lensing measurements from redshiftsz ∼ 0.5–5 are thus fully consistent with ΛCDM structure growth predictions based on CMB anisotropies probing primarilyz ∼ 1100. We find no evidence for a suppression of the amplitude of cosmic structure at low redshifts.