229 research outputs found
Measuring the Hubble constant with Type Ia supernovae as near-infrared standard candles
The most precise local measurements of rely on observations of Type Ia
supernovae (SNe Ia) coupled with Cepheid distances to SN Ia host galaxies.
Recent results have shown tension comparing to the value inferred from
CMB observations assuming CDM, making it important to check for
potential systematic uncertainties in either approach. To date, precise local
measurements have used SN Ia distances based on optical photometry, with
corrections for light curve shape and colour. Here, we analyse SNe Ia as
standard candles in the near-infrared (NIR), where intrinsic variations in the
supernovae and extinction by dust are both reduced relative to the optical.
From a combined fit to 9 nearby calibrator SNe with host Cepheid distances from
Riess et al. (2016) and 27 SNe in the Hubble flow, we estimate the absolute
peak magnitude mag and
(statistical) 2.7 (systematic) km s Mpc. The 2.2
statistical uncertainty demonstrates that the NIR provides a compelling avenue
to measuring SN Ia distances, and for our sample the intrinsic (unmodeled) peak
magnitude scatter is just 0.10 mag, even without light curve shape or
colour corrections. Our results do not vary significantly with different sample
selection criteria, though photometric calibration in the NIR may be a dominant
systematic uncertainty. Our findings suggest that tension in the competing
distance ladders is likely not a result of supernova systematics that
could be expected to vary between optical and NIR wavelengths, like dust
extinction. We anticipate further improvements in with a larger
calibrator sample of SNe Ia with Cepheid distances, more Hubble flow SNe Ia
with NIR light curves, and better use of the full NIR photometric data set
beyond simply the peak -band magnitude.Comment: 13 pages, replaced to match published version in A&A, code available
at https://github.com/sdhawan21/irh
SweetSpot: Near-Infrared Observations of Thirteen Type Ia Supernovae from a New NOAO Survey Probing the Nearby Smooth Hubble Flow
We present 13 Type Ia supernovae (SNe Ia) observed in the restframe
near-infrared (NIR) from 0.02 < z < 0.09 with the WIYN High-resolution Infrared
Camera (WHIRC) on the WIYN 3.5-m telescope. With only 1-3 points per light
curve and a prior on the time of maximum from the spectrum used to type the
object we measure an H-band dispersion of spectroscopically normal SNe Ia of
0.164 mag. These observations continue to demonstrate the improved standard
brightness of SNe Ia in H-band even with limited data. Our sample includes two
SNe Ia at z ~ 0.09, which represent the most distant restframe NIR H-band
observations published to date.
This modest sample of 13 NIR SNe Ia represent the pilot sample for
"SweetSpot" - a three-year NOAO Survey program that will observe 144 SNe Ia in
the smooth Hubble flow. By the end of the survey we will have measured the
relative distance to a redshift of z ~ 0.05 to 1%. Nearby Type Ia supernova (SN
Ia) observations such as these will test the standard nature of SNe Ia in the
restframe NIR, allow insight into the nature of dust, and provide a critical
anchor for future cosmological SN Ia surveys at higher redshift.Comment: 36 pages, 8 figures, Submitted to Ap
Environmental Dependence of Type Ia Supernovae in Low-Redshift Galaxy Clusters
We present an analysis of 102 type Ia supernovae (SNe Ia) in nearby (z <
0.1), x-ray selected galaxy clusters. This is the largest such sample to date
and is based on archival data primarily from ZTF and ATLAS. We divide our SNe
Ia into an inner cluster sample projected within of the cluster
center and an outer cluster sample projected between and
. We compare these to field samples of SNe Ia at similar redshifts
in both quiescent and star-forming host galaxies. Based on SALT3 fits to the
light curves, we find that the inner cluster SNe Ia have a higher fraction of
fast-evolving objects (SALT3 ) than the outer cluster or field
quiescent samples. This implies an intrinsically different population of SNe Ia
occurs in inner cluster environments, beyond known correlations based on host
galaxy alone. Our cluster samples show a strongly bimodal distribution
with a fast-evolving component that dominates the inner cluster objects
( 75%) but is just a small fraction of SNe Ia in field star-forming
galaxies ( 10%). We do not see strong evidence for variations in the
color (SALT3 ) distributions among the samples and find only minor
differences in SN Ia standardization parameters and Hubble residuals. We
suggest that the age of the stellar population drives the observed
distributions, with the oldest populations nearly exclusively producing
fast-evolving SNe Ia.Comment: Submitted to AAS journal
The First Data Release from SweetSpot: 74 Supernovae in 36 Nights on WIYN+WHIRC
SweetSpot is a three-year National Optical Astronomy Observatory (NOAO)
Survey program to observe Type Ia supernovae (SNe Ia) in the smooth Hubble flow
with the WIYN High-resolution Infrared Camera (WHIRC) on the WIYN 3.5-m
telescope. We here present data from the first half of this survey, covering
the 2011B-2013B NOAO semesters, and consisting of 493 calibrated images of 74
SNe Ia observed in the rest-frame near-infrared (NIR) from .
Because many observed supernovae require host galaxy subtraction from templates
taken in later semesters, this release contains only the 186 NIR () data
points for the 33 SNe Ia that do not require host-galaxy subtraction. The
sample includes 4 objects with coverage beginning before the epoch of B-band
maximum and 27 beginning within 20 days of B-band maximum. We also provide
photometric calibration between the WIYN+WHIRC and Two-Micron All Sky Survey
(2MASS) systems along with light curves for 786 2MASS stars observed alongside
the SNe Ia. This work is the first in a planned series of three SweetSpot Data
Releases. Future releases will include the full set of images from all 3 years
of the survey, including host-galaxy reference images and updated data
processing and host-galaxy reference subtraction. SweetSpot will provide a
well-calibrated sample that will help improve our ability to standardize
distance measurements to SNe Ia, examine the intrinsic optical-NIR colors of
SNe Ia at different epochs, explore nature of dust in other galaxies, and act
as a stepping stone for more distant, potentially space-based surveys.Comment: Published in AJ. 10 tables. 11 figures. Lightcurve plots included as
a figureset and available in source tarball. Data online at
http://www.phyast.pitt.edu/~wmwv/SweetSpot/DR1_data
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