4 research outputs found
Constraints on the frequency and mass content of r-process events derived from turbulent mixing in galactic disks
Metal-poor stars in the Milky Way (MW) halo display large star-to-star
dispersion in their r-process abundance relative to lighter elements. This
suggests a chemically diverse and unmixed interstellar medium (ISM) in the
early Universe. This study aims to help shed light on the impact of turbulent
mixing, driven by core collapse supernovae (cc-SNe), on the r-process abundance
dispersal in galactic disks. To this end, we conduct a series of simulations of
small-scale galaxy patches which resolve metal mixing mechanisms at parsec
scales. Our set-up includes cc-SNe feedback and enrichment from r-process
sources. We find that the relative rate of the r-process events to cc-SNe is
directly imprinted on the shape of the r-process distribution in the ISM with
more frequent events causing more centrally peaked distributions. We consider
also the fraction of metals that is lost on galactic winds and find that cc-SNe
are able to efficiently launch highly enriched winds, especially in smaller
galaxy models. This result suggests that smaller systems, e.g. dwarf galaxies,
may require higher levels of enrichment in order to achieve similar mean
r-process abundances as MW-like progenitors systems. Finally, we are able to
place novel constraints on the production rate of r-process elements in the MW,
, imposed by accurately reproducing the mean and
dispersion of [Eu/Fe] in metal-poor stars. Our results are consistent with
independent estimates from alternate methods and constitute a significant
reduction in the permitted parameter space.Comment: 20 pages, 12 figures, 3 appendices. Accepted for publication in The
Astrophysical Journa
The Young Supernova Experiment: Survey Goals, Overview, and Operations
Time domain science has undergone a revolution over the past decade, with
tens of thousands of new supernovae (SNe) discovered each year. However,
several observational domains, including SNe within days or hours of explosion
and faint, red transients, are just beginning to be explored. Here, we present
the Young Supernova Experiment (YSE), a novel optical time-domain survey on the
Pan-STARRS telescopes. Our survey is designed to obtain well-sampled
light curves for thousands of transient events up to . This
large sample of transients with 4-band light curves will lay the foundation for
the Vera C. Rubin Observatory and the Nancy Grace Roman Space Telescope,
providing a critical training set in similar filters and a well-calibrated
low-redshift anchor of cosmologically useful SNe Ia to benefit dark energy
science. As the name suggests, YSE complements and extends other ongoing
time-domain surveys by discovering fast-rising SNe within a few hours to days
of explosion. YSE is the only current four-band time-domain survey and is able
to discover transients as faint 21.5 mag in and 20.5 mag in
, depths that allow us to probe the earliest epochs of stellar explosions.
YSE is currently observing approximately 750 square degrees of sky every three
days and we plan to increase the area to 1500 square degrees in the near
future. When operating at full capacity, survey simulations show that YSE will
find 5000 new SNe per year and at least two SNe within three days of
explosion per month. To date, YSE has discovered or observed 8.3% of the
transient candidates reported to the International Astronomical Union in 2020.
We present an overview of YSE, including science goals, survey characteristics
and a summary of our transient discoveries to date.Comment: ApJ, in press; more information at https://yse.ucsc.edu
Recommended from our members
The Young Supernova Experiment Data Release 1 (YSE DR1): Light Curves and Photometric Classification of 1975 Supernovae
Abstract
We present the Young Supernova Experiment Data Release 1 (YSE DR1), comprised of processed multicolor PanSTARRS1 griz and Zwicky Transient Facility (ZTF) gr photometry of 1975 transients with host–galaxy associations, redshifts, spectroscopic and/or photometric classifications, and additional data products from 2019 November 24 to 2021 December 20. YSE DR1 spans discoveries and observations from young and fast-rising supernovae (SNe) to transients that persist for over a year, with a redshift distribution reaching z ≈ 0.5. We present relative SN rates from YSE’s magnitude- and volume-limited surveys, which are consistent with previously published values within estimated uncertainties for untargeted surveys. We combine YSE and ZTF data, and create multisurvey SN simulations to train the ParSNIP and SuperRAENN photometric classification algorithms; when validating our ParSNIP classifier on 472 spectroscopically classified YSE DR1 SNe, we achieve 82% accuracy across three SN classes (SNe Ia, II, Ib/Ic) and 90% accuracy across two SN classes (SNe Ia, core-collapse SNe). Our classifier performs particularly well on SNe Ia, with high (>90%) individual completeness and purity, which will help build an anchor photometric SNe Ia sample for cosmology. We then use our photometric classifier to characterize our photometric sample of 1483 SNe, labeling 1048 (∼71%) SNe Ia, 339 (∼23%) SNe II, and 96 (∼6%) SNe Ib/Ic. YSE DR1 provides a training ground for building discovery, anomaly detection, and classification algorithms, performing cosmological analyses, understanding the nature of red and rare transients, exploring tidal disruption events and nuclear variability, and preparing for the forthcoming Vera C. Rubin Observatory Legacy Survey of Space and Time.</jats:p
The Young Supernova Experiment Data Release 1 (YSE DR1) Light Curves
This is the official Zenodo data release of the Young Supernova Experiment Public Data Release 1 (YSE DR1) light curves associated with the paper, "The Young Supernova Experiment Data Release 1 (YSE DR1): Light Curves and Photometric Classification of 1975 Supernovae". YSE DR1 is comprised of processed multi-color Pan-STARRS1 (PS1)-griz and Zwicky Transient Facility (ZTF)-gr photometry lightcurve files in the SNANA data format of 1975 transients with host galaxy associations, redshifts, spectroscopic/photometric classifications, and additional data products from November 24th, 2019 to December 20, 2021. See Aleo et al. (2022) for details. "yse_dr1_zenodo.tar.gz" -- All lightcurve data with no cut on signal to noise (S/N). "yse_dr1_zenodo_snr_geq_4.tar.gz" -- All lightcurve data with S/N &gt;= 4. This can be used to recreate the analysis in Aleo et al. (2022). "parsnip_results_for_ysedr1_table_A1_full_for_online" -- The full version of Table~C2 in Aleo et al. (2022). The full ParSNIP (tertiary classification) results for YSE DR1. NOTE: An example tutorial on how to download the YSE DR1 data (full sample, spec sample, phot sample), grab metadata, and recreate a plot from the paper can be found on Github.</span