165 research outputs found
Serendipitous discovery of a strong-lensed galaxy in integral field spectroscopy from MUSE
2MASX J04035024-0239275 is a bright red elliptical galaxy at redshift 0.0661
that presents two extended sources at 2\arcsec~to the north-east and
1\arcsec~to the south-west. The sizes and surface brightnesses of the two blue
sources are consistent with a gravitationally-lensed background galaxy. In this
paper we present MUSE observations of this galaxy from the All-weather MUse
Supernova Integral-field Nearby Galaxies (AMUSING) survey, and report the
discovery of a background lensed galaxy at redshift 0.1915, together with other
15 background galaxies at redshifts ranging from 0.09 to 0.9, that are not
multiply imaged. We have extracted aperture spectra of the lens and all the
sources and fit the stellar continuum with STARLIGHT to estimate their stellar
and emission line properties. A trace of past merger and active nucleus
activity is found in the lensing galaxy, while the background lensed galaxy is
found to be star-forming. Modeling the lensing potential with a singular
isothermal ellipsoid, we find an Einstein radius of 1\farcs450\farcs04,
which corresponds to 1.9 kpc at the redshift of the lens and it is much smaller
than its effective radius ( 9\arcsec). Comparing the Einstein
mass and the STARLIGHT stellar mass within the same aperture yields a dark
matter fraction of \% within the Einstein radius. The advent of
large surveys such as the Large Synoptic Survey Telescope (LSST) will discover
a number of strong-lensed systems, and here we demonstrate how wide-field
integral field spectroscopy offers an excellent approach to study them and to
precisely model lensing effects.Comment: 12 pages, 12 Figures, 4 Tables. Accepted in MNRA
Single-object Imaging and Spectroscopy to Enhance Dark Energy Science from LSST
Single-object imaging and spectroscopy on telescopes with apertures ranging
from ~4 m to 40 m have the potential to greatly enhance the cosmological
constraints that can be obtained from LSST. Two major cosmological probes will
benefit greatly from LSST follow-up: accurate spectrophotometry for nearby and
distant Type Ia supernovae will expand the cosmological distance lever arm by
unlocking the constraining power of high-z supernovae; and cosmology with time
delays of strongly-lensed supernovae and quasars will require additional
high-cadence imaging to supplement LSST, adaptive optics imaging or
spectroscopy for accurate lens and source positions, and IFU or slit
spectroscopy to measure detailed properties of lens systems. We highlight the
scientific impact of these two science drivers, and discuss how additional
resources will benefit them. For both science cases, LSST will deliver a large
sample of objects over both the wide and deep fields in the LSST survey, but
additional data to characterize both individual systems and overall systematics
will be key to ensuring robust cosmological inference to high redshifts.
Community access to large amounts of natural-seeing imaging on ~2-4 m
telescopes, adaptive optics imaging and spectroscopy on 8-40 m telescopes, and
high-throughput single-target spectroscopy on 4-40 m telescopes will be
necessary for LSST time domain cosmology to reach its full potential. In two
companion white papers we present the additional gains for LSST cosmology that
will come from deep and from wide-field multi-object spectroscopy.Comment: Submitted to the call for Astro2020 science white paper
The delay time distribution of supernovae from integral-field spectroscopy of nearby galaxies
Constraining the delay-time distribution (DTD) of different supernova (SN)
types can shed light on the timescales of galaxy chemical enrichment and
feedback processes affecting galaxy dynamics, and SN progenitor properties.
Here, we present an approach to recover SN DTDs based on integral field
spectroscopy (IFS) of their host galaxies. Using a statistical analysis of a
sample of 116 supernovae in 102 galaxies, we evaluate different DTD models for
SN types Ia (73), II (28) and Ib/c (15). We find the best SN Ia DTD fit to be a
power law with an exponent (50\% confidence interval),
and a time delay (between star formation and the first SNe) (50\% C.I.). For core collapse (CC) SNe, both of the
Zapartas et al. (2017) DTD models for single and binary stellar evolution are
consistent with our results. For SNe II and Ib/c, we find a correlation with a
Gaussian DTD model with and (50\% C.I.) respectively. This analysis demonstrates that
integral field spectroscopy opens a new way of studying SN DTD models in the
local universe
HII regions in the CALIFA survey: I. Catalog presentation
We present a new catalogue of H II regions based on the integral field spectroscopy (IFS) data of the extended CALIFA and PISCO samples. The selection of H II regions was based on two assumptions: a clumpy structure with high contrast of H α emission and an underlying stellar population comprising young stars. The catalogue provides the spectroscopic information of 26 408 individual regions corresponding to 924 galaxies, including the flux intensities and equivalent widths of 51 emission lines covering the wavelength range between 3745 and 7200 Ã…. To our knowledge, this is the largest catalogue of spectroscopic properties of H II regions. We explore a new approach to decontaminate the emission lines from diffuse ionized gas contribution. This diffuse gas correction was estimated to correct every emission line within the considered spectral range. With the catalogue of H II regions corrected, new demarcation lines are proposed for the classical diagnostic diagrams. Finally, we study the properties of the underlying stellar populations of the H II regions. It was found that there is a direct relationship between the ionization conditions on the nebulae and the properties of stellar populations besides the physicals condition on the ionized regions.Fil: Espinosa Ponce, Carlos. Universidad Nacional Autónoma de México; MéxicoFil: Sánchez, S. F.. Universidad Nacional Autónoma de México; MéxicoFil: Morisset, C.. Universidad Nacional Autónoma de México; MéxicoFil: Barrera Ballesteros, J. K.. Universidad Nacional Autónoma de México; MéxicoFil: Galbany, LluÃs. Universidad de Granada; EspañaFil: GarcÃa Benito, Rubén. Instituto de AstrofÃsica de AndalucÃa; España. Consejo Superior de Investigaciones CientÃficas; EspañaFil: Lacerda, E. A. D.. Universidad Nacional Autónoma de México; MéxicoFil: Mast, Damian. Archivo del Observatorio Astronomico de Cordoba ; Observatorio Astronomico de Cordoba ; Rectorado ; Universidad Nacional de Cordoba; . Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Córdoba; Argentin
Spatial metallicity distribution statistics at pc scales in the AMUSING++ nearby galaxy sample
We analyse the spatial statistics of the 2D gas-phase oxygen abundance
distributions in a sample of 219 local galaxies. We introduce a new adaptive
binning technique to enhance the signal-to-noise ratio of weak lines, which we
use to produce well-filled metallicity maps for these galaxies. We show that
the two-point correlation functions computed from the metallicity distributions
after removing radial gradients are in most cases well described by a simple
injection-diffusion model. Fitting the data to this model yields the
correlation length , which describes the characteristic
interstellar medium mixing length scale. We find typical correlation lengths
kpc, with a strong correlation between and
stellar mass, star formation rate, and effective radius, a weak correlation
with Hubble type, and significantly elevated values of in
interacting or merging galaxies. We show that the trend with star formation
rate can be reproduced by a simple transport+feedback model of interstellar
medium turbulence at high star formation rate, and plausibly also at low star
formation rate if dwarf galaxy winds have large mass-loading factors. We also
report the first measurements of the injection width that describes the initial
radii over which supernova remnants deposit metals. Inside this radius the
metallicity correlation function is not purely the product of a competition
between injection and diffusion. We show that this size scale is generally
smaller than 60 pc.Comment: 18 pages, 18 figures, 1 table, submitted to MNRAS. Comments are
welcom
Wide-field Multi-object Spectroscopy to Enhance Dark Energy Science from LSST
LSST will open new vistas for cosmology in the next decade, but it cannot
reach its full potential without data from other telescopes. Cosmological
constraints can be greatly enhanced using wide-field ( deg total
survey area), highly-multiplexed optical and near-infrared multi-object
spectroscopy (MOS) on 4-15m telescopes. This could come in the form of
suitably-designed large surveys and/or community access to add new targets to
existing projects. First, photometric redshifts can be calibrated with high
precision using cross-correlations of photometric samples against spectroscopic
samples at that span thousands of sq. deg. Cross-correlations of
faint LSST objects and lensing maps with these spectroscopic samples can also
improve weak lensing cosmology by constraining intrinsic alignment systematics,
and will also provide new tests of modified gravity theories. Large samples of
LSST strong lens systems and supernovae can be studied most efficiently by
piggybacking on spectroscopic surveys covering as much of the LSST
extragalactic footprint as possible (up to square degrees).
Finally, redshifts can be measured efficiently for a high fraction of the
supernovae in the LSST Deep Drilling Fields (DDFs) by targeting their hosts
with wide-field spectrographs. Targeting distant galaxies, supernovae, and
strong lens systems over wide areas in extended surveys with (e.g.) DESI or MSE
in the northern portion of the LSST footprint or 4MOST in the south could
realize many of these gains; DESI, 4MOST, Subaru/PFS, or MSE would all be
well-suited for DDF surveys. The most efficient solution would be a new
wide-field, highly-multiplexed spectroscopic instrument in the southern
hemisphere with m aperture. In two companion white papers we present gains
from deep, small-area MOS and from single-target imaging and spectroscopy.Comment: Submitted to the call for Astro2020 science white papers; tables with
estimates of telescope time needed for a supernova host survey can be seen at
http://d-scholarship.pitt.edu/id/eprint/3604
Recovering lost light: discovery of supernova remnants with integral field spectroscopy
We present results from a systematic search for broad ( 400 \kms) \ha\
emission in Integral Field Spectroscopy data cubes of 1200 nearby
galaxies obtained with PMAS and MUSE. We found 19 unique regions that pass our
quality cuts, four of which match the locations of previously discovered SNe:
one Type IIP, and three Type IIn, including the well-known SN 2005ip. We
suggest that these objects are young Supernova Remnants, with bright and broad
\ha\ emission powered by the interaction between the SN ejecta and dense
circumstellar material. The stellar ages measured at the location of these SNR
candidates are systematically lower by about 0.5 dex than those measured at the
location of core collapse SNe, implying that their progenitors might be shorter
lived and therefore more massive than a typical CC SN progenitor. The methods
laid out in this work open a new window into the study of nearby SNe with
Integral Field Spectroscopy.Comment: 16 pages, 10 figures, submitted to AAS journal
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