- ID:
- ivo://CDS.VizieR/J/ApJ/889/5
- Title:
- HST obs. of Mira variables in the SNIa host NGC1559
- Short Name:
- J/ApJ/889/5
- Date:
- 17 Jan 2022 11:46:55
- Publisher:
- CDS
- Description:
- We present year-long, near-infrared Hubble Space Telescope (HST) WFC3 observations used to search for Mira variables in NGC 1559, the host galaxy of the Type Ia supernova (SN Ia) SN 2005df. This is the first dedicated search for Miras, highly evolved low-mass stars, in an SNIa host, and subsequently the first calibration of the SN Ia luminosity using Miras in a role historically played by Cepheids. We identify a sample of 115 O-rich Miras with P<400days based on their light-curve properties. We find that the scatter in the Mira period-luminosity relation (PLR) is comparable to Cepheid PLRs seen in SN Ia host galaxies. Using a sample of O-rich Miras discovered in NGC 4258 with HSTF160W and its maser distance, we measure a distance modulus for NGC1559 of {mu}_1559_=31.41+/-0.050(statistical)+/-0.060(systematic)mag. Based on the light curve of the normal, well-observed, low-reddening SN 2005df, we obtain a measurement of the fiducial SN Ia absolute magnitude of M_B_^0^=-19.27+/-0.13mag. With the Hubble diagram of SNe Ia we find H_0_=72.7+/-4.6km/s/Mpc. Combining the calibration from the NGC 4258 megamaser and the Large Magellanic Cloud detached eclipsing binaries gives a best value of H_0_=73.3+/-4.0km/s/Mpc. This result is within 1{sigma} of the Hubble constant derived using Cepheids and multiple calibrating SNe Ia. This is the first of four expected calibrations of the SN Ia luminosity from Miras that should reduce the error in H_0_ via Miras to ~3%. In light of the present Hubble tension and JWST, Miras have utility in the extragalactic distance scale to check Cepheid distances or calibrate nearby SNe in early-type host galaxies that would be unlikely targets for Cepheid searches.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/902/26
- Title:
- HST opt. & H-band obs. of Cepheids in NGC4151
- Short Name:
- J/ApJ/902/26
- Date:
- 14 Mar 2022 07:44:50
- Publisher:
- CDS
- Description:
- We derive a distance of 15.8+/-0.4Mpc to the archetypal Seyfert 1 galaxy NGC 4151 based on the near-infrared Cepheid period-luminosity relation and new Hubble Space Telescope multiband imaging. This distance determination, based on measurements of 35 long-period (P>25d) Cepheids, will support the absolute calibration of the supermassive black hole mass in this system, as well as studies of the dynamics of the feedback or feeding of its active galactic nucleus.
- ID:
- ivo://CDS.VizieR/J/AJ/130/1083
- Title:
- HST photometry in the wing of the SMC
- Short Name:
- J/AJ/130/1083
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used the Wide Field Planetary Camera 2 (WFPC2) on the Hubble Space Telescope to image a star field in the wing of the Small Magellanic Cloud (SMC), near the HII region N81. The images were taken in the F336W, F547M, F675W, and F814W filters. From photometry of stars in this field, we construct color-magnitude diagrams (CMDs) for about 4200 stars and compare them with theoretical isochrones.
1074. HST photometry of M4
- ID:
- ivo://CDS.VizieR/J/ApJS/120/265
- Title:
- HST photometry of M4
- Short Name:
- J/ApJS/120/265
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents a detailed description of the acquisition and processing of a large body of imaging data for three fields in the globular cluster M4 taken with the Wide Field and Planetary Camera 2 aboard the Hubble Space Telescope. Analysis with the ALLFRAME package yielded the deepest photometry yet obtained for this cluster. The resulting data set for 4708 stars (positions and calibrated photometry in V, I, and, in two fields, U) spanning approximately six cluster core radii is presented. The scientific analysis is deferred to three companion papers, which investigate the significant white dwarf population discovered and the main-sequence population.
- ID:
- ivo://CDS.VizieR/J/ApJ/703/42
- Title:
- HST photometry of M87 globular clusters
- Short Name:
- J/ApJ/703/42
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the M87 GC system using deep, archival HST/ACS imaging with the F606W and F814W filters, in which we find a significant color-magnitude relation for the metal-poor globular clusters (GCs). The slope of this relation in the I versus V-I color-magnitude diagram ({gamma}_I_=-0.024+/-0.006) is perfectly consistent with expectations based on previously published results using data from the ACS Virgo Cluster Survey. We show that previously measured half-light radii of M87 GCs from best-fit PSF-convolved King models are consistent with the more accurate measurements in this study, and we also explain how the color-magnitude relation for metal-poor GCs is real and cannot be an artifact of the photometry. We fit Gaussian and evolved Schechter functions to the luminosity distribution of GCs across all colors, as well as divided into blue and red subpopulations, finding that the blue GCs have a brighter mean luminosity and a narrower distribution than the red GCs. Finally, we present a catalog of astrometry and photometry for 2250 M87 GCs.
- ID:
- ivo://CDS.VizieR/J/ApJ/861/99
- Title:
- HSTPROMO cat. VI. Improved analysis of NGC362
- Short Name:
- J/ApJ/861/99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an improved data-reduction technique to obtain high-precision proper motions (PMs) of globular clusters (GCs) using Hubble Space Telescope data. The new reduction is superior to the one presented in the first paper of this series for the faintest sources in very crowded fields. We choose the GC NGC 362 as a benchmark to test our new procedures. We measure PMs of 117450 sources in the field, showing that we are able to obtain a PM precision better than 10{mu}as/yr for bright stars. We make use of this new PM catalog of NGC 362 to study the cluster's internal kinematics. We investigate the velocity dispersion profiles of the multiple stellar populations hosted by NGC 362 and find new pieces of information on the kinematics of first- and second- generation stars. We analyze the level of energy equipartition of the cluster and find direct evidence for its post-core-collapsed state from kinematic arguments alone. We refine the dynamical mass of the blue stragglers (BSs) and study possible kinematic differences between BSs formed by collisions and mass transfer. We also measure no significant cluster rotation in the plane of the sky. Finally, we measure the absolute PM of NGC 362 and of the background stars belonging to the Small Magellanic Cloud, finding a good agreement with previous estimates in the literature. We make the PM catalog publicly available.
- ID:
- ivo://CDS.VizieR/J/AJ/161/51
- Title:
- HST spectral light curve of HAT-P-41
- Short Name:
- J/AJ/161/51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive analysis of the 0.3-5{mu}m transit spectrum for the inflated hot Jupiter HAT-P-41b. The planet was observed in transit with Hubble STIS and WFC3 as part of the Hubble Panchromatic Comparative Exoplanet Treasury (PanCET) program, and we combine those data with warm Spitzer transit observations. We extract transit depths from each of the data sets, presenting the STIS transit spectrum (0.29-0.93{mu}m) for the first time. We retrieve the transit spectrum both with a free-chemistry retrieval suite (AURA) and a complementary chemical equilibrium retrieval suite (PLATON) to constrain the atmospheric properties at the day-night terminator. Both methods provide an excellent fit to the observed spectrum. Both AURA and PLATON retrieve a metal-rich atmosphere for almost all model assumptions (most likely O/H ratio of log_10_Z/Z{odot}=1.46_-0.68_^+0.53^ and log_10_Z/Z{odot}=2.33_-0.25_^+0.23^, respectively); this is driven by a 4.9{sigma} detection of H_2_O as well as evidence of gas absorption in the optical (>2.7{sigma} detection) due to Na, AlO, and/or VO/TiO, though no individual species is strongly detected. Both retrievals determine the transit spectrum to be consistent with a clear atmosphere, with no evidence of haze or high-altitude clouds. Interior modeling constraints on the maximum atmospheric metallicity (log_10_Z/Z{odot}<1.7) favor the AURA results. The inferred elemental oxygen abundance suggests that HAT-P-41b has one of the most metal-rich atmospheres of any hot Jupiters known to date. Overall, the inferred high metallicity and high inflation make HAT-P-41b an interesting test case for planet formation theories.
- ID:
- ivo://CDS.VizieR/J/ApJ/896/81
- Title:
- HST survey of ONC in H2O 1.4um abs. band. III.
- Short Name:
- J/ApJ/896/81
- Date:
- 11 Mar 2022
- Publisher:
- CDS
- Description:
- We present new results concerning the substellar binary population in the Orion Nebula Cluster (ONC). Using the Karhunen-Loeve Image Projection algorithm, we have reprocessed images taken with the IR channel of the Wide Field Camera 3 mounted on the Hubble Space Telescope to unveil faint, close companions in the wings of the stellar point-spread functions. Starting with a sample of 1392 bona fide unsaturated cluster members, we detect 39 close-pair cluster candidates with separation 0.16"-0.77". The primary masses span a range Mp~0.015-1.27M_{sun}_, whereas for the companions we derive Mc~0.004-0.54M_{sun}_. Of these 39 binary systems, 18 were already known, while the remaining 21 are new detections. Correcting for completeness and combining our catalog with previously detected ONC binaries, we obtain an overall binary fraction of 11.5%+/-0.9%. Compared to other star-forming regions, our multiplicity function is ~2 times smaller than, for example, Taurus, while compared to the binaries in the field we obtain comparable values. We analyze the mass functions of the binaries, finding differences between the mass distributions of binaries and single stars and between primary and companion mass distributions. The mass ratio shows a bottom-heavy distribution with median value Mc/Mp~0.25. Overall, our results suggest that ONC binaries may represent a template for the typical population of field binaries, supporting the hypothesis that the ONC may be regarded as a most typical star-forming region in the Milky Way.
- ID:
- ivo://CDS.VizieR/J/ApJ/896/79
- Title:
- HST survey of ONC in H20 1.4um abs. band. I.
- Short Name:
- J/ApJ/896/79
- Date:
- 11 Mar 2022
- Publisher:
- CDS
- Description:
- In order to obtain a complete census of the stellar and substellar population, down to a few M_Jup_ in the ~1Myr old Orion Nebula Cluster, we used the infrared channel of the Wide Field Camera 3 of the Hubble Space Telescope with the F139M and F130N filters. These bandpasses correspond to the 1.4{mu}m H2O absorption feature and an adjacent line-free continuum region. Out of 4504 detected sources, 3352 (about 75%) appear fainter than m130=14 (Vega mag) in the F130N filter, a brightness corresponding to the hydrogen- burning limit mass (M~0.072M_{sun}_) at ~1Myr. Of these, however, only 742 sources have a negative F130M-F139N color index, indicative of the presence of H2O vapor in absorption, and can therefore be classified as bona fide M and L dwarfs, with effective temperatures T<~2850K at an assumed 1Myr cluster age. On our color-magnitude diagram (CMD), this population of sources with H2O absorption appears clearly distinct from the larger background population of highly reddened stars and galaxies with positive F130M-F139N color index and can be traced down to the sensitivity limit of our survey, m130~21.5, corresponding to a 1Myr old ~3M_Jup_ planetary-mass object under about 2mag of visual extinction. Theoretical models of the BT-Settl family predicting substellar isochrones of 1, 2, and 3 Myr down to ~1M_Jup_ fail to reproduce the observed H2O color index at M<~20M_Jup_. We perform a Bayesian analysis to determine extinction, mass, and effective temperature of each substellar member of our sample, together with its membership probability.
- ID:
- ivo://CDS.VizieR/J/ApJS/207/10
- Title:
- HST Treasury Program on the ONC
- Short Name:
- J/ApJS/207/10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Hubble Space Telescope (HST) Treasury Program on the Orion Nebula Cluster (ONC) has used 104 orbits of HST time to image the Great Orion Nebula region with the Advanced Camera for Surveys (ACS), the Wide-Field/Planetary Camera 2 (WFPC2), and the Near-Infrared Camera and Multi-Object Spectrograph (NICMOS) instrument in 11 filters ranging from the U band to the H band equivalent of HST. The program has been intended to perform the definitive study of the stellar component of the ONC at visible wavelengths, addressing key questions like the cluster initial mass function, age spread, mass accretion, binarity, and circumstellar disk evolution. The scanning pattern allowed us to cover a contiguous field of approximately 600 arcmin2 with both ACS and WFPC2, with a typical exposure time of approximately 11 minutes per ACS filter, corresponding to a point source depth AB(F435W) = 25.8 and AB(F775W) = 25.2 with 0.2 mag of photometric error. We describe the observations, data reduction, and data products, including images, source catalogs, and tools for quick look preview. In particular, we provide ACS photometry for 3399 stars, most of them detected at multiple epochs; WFPC2 photometry for 1643 stars, 1021 of them detected in the U band; and NICMOS JH photometry for 2116 stars. We summarize the early science results that have been presented in a number of papers.
