A5018971551- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astrophysical Phenomena and Observations
- Astrophysics and Star Formation Studies
- Scientific Research and Discoveries
- Romani and Gypsy Studies
- Spacecraft and Cryogenic Technologies
- Calibration and Measurement Techniques
- Adaptive optics and wavefront sensing
- Forensic and Genetic Research
- Astrophysics and Cosmic Phenomena
- Remote Sensing in Agriculture
Carnegie Observatories
2022
Carnegie Institution for Science
2022
University of Chicago
2014-2019
The University of Melbourne
1965
We present a new and independent determination of the local value Hubble constant based on calibration Tip Red Giant Branch (TRGB) applied to Type Ia supernovae (SNeIa). find Ho = 69.8 +/- 0.8 (+/-1.1\% stat) 1.7 (+/-2.4\% sys) km/sec/Mpc. The TRGB method is both precise accurate, parallel to, but Cepheid distance scale. Our sits midway in range defined by current tension. It agrees at 1.2-sigma level with that Planck 2018 estimate, 1.7-sigma SHoES measurement distances have been measured...
We present an overview of the Carnegie-Chicago Hubble Program, ongoing program to obtain a 3 per cent measurement constant using alternative methods traditional Cepheid distance scale. aim establish completely independent route RR Lyrae variables, tip red giant branch (TRGB), and Type Ia supernovae (SNe Ia). This ladder can be applied galaxies any Type, inclination, and, utilizing old stars in low density environments, is robust degenerate effects metallicity interstellar extinction. Given...
ABSTRACT RR Lyrae stars have long been popular standard candles, but significant advances in methodology and technology made recent years to increase their precision as distance indicators. We present multiwavelength (optical UBVRcIc Gaia G, BP, RP; near-infrared JHKs; mid-infrared [3.6], [4.5]) period–luminosity–metallicity (PLZ), period–Wesenheit–metallicity (PWZ) relations, calibrated using photometry obtained from the Carnegie Program parallaxes second data release for 55 Galactic field...
The Carnegie-Chicago Hubble Program seeks to anchor the distance scale of Type Ia supernovae via Tip Red Giant Branch (TRGB). Based on deep $Hubble$ $Space$ $Telescope$ ACS/WFC imaging, we present an analysis TRGB for metal-poor halo NGC 1365, a giant spiral galaxy in Fornax Cluster that is host supernova SN2012fr. We have measured its extinction-corrected magnitude be F814W $= 27.34 \pm 0.03_{stat} \pm0.01_{sys}$ mag. In advance future direct calibration by $Gaia$, set provisional...
Abstract The Carnegie-Chicago Hubble Program is undertaking a re-calibration of the extragalactic distance scale, using SNe Ia that are tied to Tip Red Giant Branch (TRGB) distances local galaxies. We present here deep Space Telescope ACS/WFC imaging resolved stellar populations in metal-poor halos SN Ia-host galaxies NGC 4424, 4526, and 4536. These three Virgo constellation prime targets for calibrating scale given their relative proximity universe low line-of-sight reddenings. Anchoring...
IC 1613 is an isolated dwarf galaxy within the Local Group. Low foreground and internal extinction, low metallicity, crowding make it invaluable testbed for calibration of local distance ladder. We present new, high-fidelity estimates to via its Tip Red Giant Branch (TRGB) RR Lyrae (RRL) variables as part Carnegie-Chicago Hubble Program, which seeks alternate route \ho using Population II stars. have measured a TRGB magnitude I=20.35+/-0.01 (statistical)+/-0.01 (systematic) wide-field...
We determine the distances to Type Ia Supernova host galaxies M66 (NGC 3627) and M96 3368) of Leo I Group using Tip Red Giant Branch (TRGB) method. target stellar halos these Hubble Space Telescope ACS/WFC in F606W F814W bandpasses. By pointing we sample RGB stars predominantly Population II, minimize host-galaxy reddening, significantly reduce effects source crowding. Our absolute calibration I-band TRGB is based on a recent detached eclipsing binary distance Large Magellanic Cloud. With...
The non-linear, scale-dependent bias in the mass distribution of galaxies and underlying dark matter is a key systematic affecting extraction cosmological parameters from galaxy clustering. Using 95 million haloes Millennium-XXL N-body simulation, we find that scale independent only for k < 0.1 h Mpc−1 today (z = 0) 0.2 at z 0.7. We test analytic halo models against our simulation measurements model Tinker et al. accurate to better than 5 per cent 0. However, results are fitted by an...
Abstract The Carnegie–Chicago Hubble Program (CCHP) is recalibrating the extragalactic SN Ia distance scale using exclusively Population II stars. This effort focuses on Tip of Red Giant Branch (TRGB) method, whose systematics are entirely independent I Cepheid-based determinations that have long served as calibrators for scale. We present deep Space Telescope imaging low surface density and line-of-sight reddening halos two galaxies, NGC 1448 1316, each which been hosts to recent events....
Abstract Many studies have shown that RR Lyrae variable stars (RRL) are powerful stellar tracers of Galactic halo structure and satellite galaxies. The Dark Energy Survey (DES), with its deep wide coverage ( g ∼ 23.5 mag in a single exposure; over 5000 deg 2 ) provides rich opportunity to search for substructures out the edge Milky Way halo. However, sparse unevenly sampled multiband light curves from DES wide-field survey (a median four observations each grizY first three years) pose...
We present a new empirical \(JHK\) absolute calibration of the tip red giant branch (TRGB) in Large Magellanic Cloud (LMC). use published data from extensive \emph{Near-Infrared Synoptic Survey} containing 3.5 million stars, which 65,000 are giants that fall within one magnitude TRGB. Adopting TRGB slopes companion study isolated dwarf galaxy IC\,1613 as well an LMC distance modulus \(\mu_0 = \)~18.49~mag (geometric) detached eclipsing binaries, we derive zero-points for near-infrared For...
Based on observations from the \emph{FourStar} near-infrared camera 6.5m Baade-Magellan telescope at Las Campanas, Chile, we present calibrations of $JHK$ luminosities stars defining tip red giant branch (TRGB) in halo Local Group dwarf galaxy IC 1613. We employ metallicity-independent (rectified) T-band magnitudes---constructed using $J,H$ and $K$-band magnitudes both $(J-H)~ \& ~(J-K)$ colors order to flatten upward-sloping tips as otherwise seen their apparent color-magnitude diagrams....
Abstract The Carnegie-Chicago Hubble Program (CCHP) is building a direct path to the constant ( H 0 ) using Population II stars as calibrator of Type Ia supernova (SN Ia)-based distance scale. This calibrate SNe independent systematics in traditional Cepheid-based technique. In this paper, we present M101, host SN 2011fe, I -band tip red giant branch (TRGB) based on observations from ACS/WFC instrument Space Telescope . CCHP targets halo where there little no galaxy dust, isolated nearly all...
Abstract We determine the distance to Sculptor Dwarf Spheroidal via three Population II stellar indicators: (a) Tip of Red Giant Branch (TRGB), (b) RR Lyrae variables (RRLs), and (c) ridgeline blue horizontal branch (HB). High signal-to-noise, wide-field VI imaging that covers an area <?CDATA $48^{\prime} \,\times \,48^{\prime} $?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>48</mml:mn> <mml:mo accent="false">′</mml:mo> <mml:mspace width="0.25em" />...
Abstract We present photometry of 30 Galactic RR Lyrae variables taken with HST WFC3/IR for the Carnegie-Chicago Hubble Program . These measurements form base distance-ladder that comprise a pure Population II to measurement H o at an accuracy 3%. data are same instrument and filter (F160W) as our observations stars in external galaxies so minimize sources systematic error calibration extragalactic distance scale. calculate mean magnitudes based on one three each star using star-by-star...