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SN 2017gmr: An Energetic Type II-P Supernova with Asymmetries
We present high-cadence UV, optical, and near-infrared data on the luminous Type II-P supernova SN 2017gmr from hours after discovery through the first 180 days. SN 2017gmr does not show signs of narrow, high-ionization emission lines in the early optical spectra, yet the optical light-curve evolution suggests that an extra energy source from circumstellar medium (CSM) interaction must be present for at least 2 days after explosion. Modeling of the early light curve indicates a ~500 R ⊙ progenitor radius, consistent with a rather compact red supergiant, and late-time luminosities indicate that up to 0.130 ± 0.026 M ⊙ of 56Ni are present, if the light curve is solely powered by radioactive decay, although the 56Ni mass may be lower if CSM interaction contributes to the post-plateau luminosity. Prominent multipeaked emission lines of Hα and [O i] emerge after day 154, as a result of either an asymmetric explosion or asymmetries in the CSM. The lack of narrow lines within the first 2 days of explosion in the likely presence of CSM interaction may be an example of close, dense, asymmetric CSM that is quickly enveloped by the spherical supernova ejecta.NSFNational Science Foundation (NSF) [AST-1813825, AST-1515559, AST-1821987, 1821967, AST-1813176, AST-1313484, 1829740]; Department of Science and Technology (DST), Govt. of IndiaDepartment of Science & Technology (India); Indo-US Science and Technology Forum (IUSSTF); LSSTC Data Science Fellowship Program - LSSTC; Brinson Foundation; Moore FoundationGordon and Betty Moore Foundation; project "Transient Astrophysical Objects" of the National Research, Development and Innovation Office (NKFIH), Hungary - European Union [GINOP-2-3-2-15-2016-00033]; Chinese Academy of Sciences (CAS)Chinese Academy of Sciences; Swedish Research Council (Vetenskapsradet)Swedish Research Council; Swedish National Space Board; research environment grant "Gravitational Radiation and Electromagnetic Astrophysical Transients (GREAT)"; Packard FoundationThe David & Lucile Packard Foundation; "Millennium Institute of Astrophysics (MAS)" of the Iniciativa Cientifica Milenio del Ministerio Economia, Fomento y Turismo de Chile [IC120009]; CONICYT PAI/INDUSTRIA [79090016]; Science and Engineering Research Board (SERB) under the Department of Science AMP; Technology, Govt. of India [PDF/2016/001563]; Ministry of Economy, Development, and Tourism's Millennium Science Inititative [IC120009]; H2020 through an ERC Starting Grant [758638]; FONDECYTComision Nacional de Investigacion Cientifica y Tecnologica (CONICYT)CONICYT FONDECYT [11170953]; Polish NCN MAESTRO grant [2014/14/A/ST9/00121]; PRIN INAF 2017 "Towards the SKA and CTA era: discovery, localisation and physics of transient sources (PI M. Giroletti)"; Independent Research Fund Denmark [8021-00170B]; VILLUM FONDEN [13261, 16599]; Spanish MICINN grant [ESP2017-82674-R]; FEDER fundsEuropean Union (EU); National Science FoundationNational Science Foundation (NSF) [AST-1613472]; National Natural Science Foundation of China (NSFC)National Natural Science Foundation of China [11325313, 11633002, 11761141001]; National Program on Key Research and Development Project [2016YFA0400803]; Open Project Program of the Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences; IDA (Instrumentation center for Danish Astrophysics); Gemini Observatory [GN-2017B-Q-52]; European Southern Observatory [099.D-0543(A)]; W. M. Keck FoundationW.M. Keck Foundation [NNH14CK55B]; National Aeronautics and Space AdministrationNational Aeronautics & Space Administration (NASA); National Science FoundationNational Science Foundation (NSF); NASAs Astrophysics Data Analysis Program [NNX13AF35G]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Caspase-1:The inflammasome and beyond
Caspase-1 plays a fundamental role in innate immunity and in several important inflammatory diseases as the protease activates the pro-inflammatory cytokines proIL-1β and proIL-18. Caspase-1 itself is activated in different inflammasome complexes, which assemble in response to a variety of exogenous and endogenous stressors. More recently, pyroptosis, a caspase-1-dependent type of programmed cell death, has been identified that is able to support secreted IL-1 and IL-18 in triggering an inflammatory response. Whereas these 'canonical' activities are well appreciated, this review also highlights less-known pathways and molecules activated by caspase-1. There is evidence that caspase-1 supports cell survival by activation of NF-κB, induction of membrane repair and regulation of unconventional secretion of certain proteins. The physiologic effects of processing of other downstream targets, such as proteins involved in glycolysis or activation of caspase-7, are less well understood. However, there is increasing evidence that caspase-1 contributes to innate and adaptive immunologic defense mechanisms, repair and pathologic conditions by the regulation of several different and partially opposing pathways
Recurring outbursts of the supernova impostor AT 2016blu in NGC 4559
We present the first photometric analysis of the supernova (SN) impostor AT
2016blu in NGC 4559. This transient was discovered by the Lick Observatory
Supernova Search in 2012 and has continued its outbursts since then. Optical
and infrared photometry of AT 2016blu reveals at least 19 outbursts in
2012-2022. Similar photometry from 1999-2009 shows no outbursts, indicating
that the star was relatively stable in the decade before discovery. Archival
{\it Hubble Space Telescope} observations suggest that the progenitor had a
minimum initial mass of M and a luminosity of L. AT 2016blu's outbursts show irregular variability with
multiple closely spaced peaks having typical amplitudes of 1-2 mag and
durations of 1-4 weeks. While individual outbursts have irregular light curves,
concentrations of these peaks recur with a period of d. Based
on this period, we predict times for upcoming outbursts in 2023 and 2024. AT
2016blu shares similarities with SN 2000ch in NGC 3432, where outbursts may
arise from periastron encounters in an eccentric binary containing a luminous
blue variable (LBV). We propose that AT 2016blu's outbursts are also driven by
interactions that intensify around periastron in an eccentric system. Intrinsic
variability of the LBV-like primary star may cause different intensity and
duration of binary interaction at each periastron passage. AT 2016blu also
resembles the periastron encounters of Carinae prior to its Great
Eruption and the erratic pre-SN eruptions of SN 2009ip. This similarity and the
onset of eruptions in the past decade hint that AT 2016blu may also be headed
for a catastrophe, making it a target of great interest.Comment: 18 pages, 14 figures, 6 tables, MNRAS Accepte
JWST Imaging of the Cartwheel Galaxy Reveals Dust Associated with SN 2021afdx
We present near- and mid-infrared (0.9-18 m) photometry of supernova
(SN) 2021afdx, which was imaged serendipitously with the James Webb Space
Telescope (JWST) as part of its Early Release Observations of the Cartwheel
Galaxy. Our ground-based optical observations show it is likely to be a Type
IIb SN, the explosion of a yellow supergiant, and its infrared spectral energy
distribution (SED) 200 days after explosion shows two distinct
components, which we attribute to hot ejecta and warm dust. By fitting models
of dust emission to the SED, we derive a dust mass of , which is the highest yet observed in a Type IIb SN
but consistent with other Type II SNe observed by the Spitzer Space Telescope.
We also find that the radius of the dust is significantly larger than the
radius of the ejecta, as derived from spectroscopic velocities during the
photospheric phase, which implies that we are seeing an infrared echo off of
preexisting dust in the progenitor environment, rather than dust newly formed
by the SN. Our results show the power of JWST to address questions of dust
formation in SNe, and therefore the presence of dust in the early universe,
with much larger samples than have been previously possible.Comment: updated to match accepted versio
SN 2014ab: An Aspherical Type IIn Supernova with Low Polarization
We present photometry, spectra, and spectropolarimetry of supernova (SN)
2014ab, obtained through days after peak brightness. SN 2014ab was a
luminous Type IIn SN ( mag) discovered after peak brightness near
the nucleus of its host galaxy, VV 306c. Prediscovery upper limits constrain
the time of explosion to within 200 days prior to discovery. While SN 2014ab
declined by mag over the course of our observations, the observed
spectrum remained remarkably unchanged. Spectra exhibit an asymmetric
emission-line profile with a consistently stronger blueshifted component,
suggesting the presence of dust or a lack of symmetry between the far side and
near side of the SN. The Pa emission line shows a profile very similar
to that of H, implying that this stronger blueshifted component is
caused either through obscuration by large dust grains, occultation by
optically thick material, or a lack of symmetry between the far side and near
side of the interaction region. Despite these asymmetric line profiles, our
spectropolarimetric data show that SN 2014ab has little detected polarization
after accounting for the interstellar polarization. This suggests that we are
seeing emission from a photosphere that has only small deviation from circular
symmetry face-on. We are likely seeing a SN IIn with nearly circular symmetry
in the plane normal to our line of sight, but with either large-grain dust or
significant asymmetry in the density of circumstellar material or SN ejecta
along our line of sight. We suggest that SN 2014ab and SN 2010jl (as well as
other SNe IIn) may be similar events viewed from different directions.Comment: 20 pages, 19 figure
SN 2017gmr: An Energetic Type II-P Supernova with Asymmetries
We present high-cadence UV, optical, and near-infrared data on the luminous Type II-P supernova SN 2017gmr from hours after discover through the first 180 days. SN 2017gmr does not show signs of narrow high-ionization emission lines in the early optical spectra, yet th optical light-curve evolution suggests that an extra energy source fro circumstellar medium (CSM) interaction must be present for at least days after explosion. Modeling of the early light curve indicates a ∼50 R ☉ progenitor radius, consistent with a rather compact re supergiant, and late-time luminosities indicate that up to 0.130 ± 0.02 M ☉ of 56Ni are present, if the light curve i solely powered by radioactive decay, although the 56Ni mas may be lower if CSM interaction contributes to the post-platea luminosity. Prominent multipeaked emission lines of Hα and [O I] emerg after day 154, as a result of either an asymmetric explosion o asymmetries in the CSM. The lack of narrow lines within the first 2 day of explosion in the likely presence of CSM interaction may be an exampl of close, dense, asymmetric CSM that is quickly enveloped by th spherical supernova eject
Identifying the SN 2022acko progenitor with JWST
We report on analysis using the James Webb Space Telescope (JWST) to identify
a candidate progenitor star of the Type II-plateau supernova SN 2022acko in the
nearby, barred spiral galaxy NGC 1300. To our knowledge, our discovery
represents the first time JWST has been used to localize a progenitor system in
pre-explosion archival Hubble Space Telescope (HST) images. We astrometrically
registered a JWST NIRCam image from 2023 January, in which the SN was
serendipitously captured, to pre-SN HST F160W and F814W images from 2017 and
2004, respectively. An object corresponding precisely to the SN position has
been isolated with reasonable confidence. That object has a spectral energy
distribution (SED) and overall luminosity consistent with a single-star model
having an initial mass possibly somewhat less than the canonical 8 Msun
theoretical threshold for core collapse (although masses as high as 9 Msun for
the star are also possible); however, the star's SED and luminosity are
inconsistent with that of a super-asymptotic giant branch star which might be a
forerunner of an electron-capture SN. The properties of the progenitor alone
imply that SN 2022acko is a relatively normal SN II-P, albeit most likely a
low-luminosity one. The progenitor candidate should be confirmed with follow-up
HST imaging at late times, when the SN has sufficiently faded. This potential
use of JWST opens a new era of identifying SN progenitor candidates at high
spatial resolution.Comment: 8 pages, substantial changes from v1, to appear in MNRA
Multi-Messenger Astronomy with Extremely Large Telescopes
The field of time-domain astrophysics has entered the era of Multi-messenger
Astronomy (MMA). One key science goal for the next decade (and beyond) will be
to characterize gravitational wave (GW) and neutrino sources using the next
generation of Extremely Large Telescopes (ELTs). These studies will have a
broad impact across astrophysics, informing our knowledge of the production and
enrichment history of the heaviest chemical elements, constrain the dense
matter equation of state, provide independent constraints on cosmology,
increase our understanding of particle acceleration in shocks and jets, and
study the lives of black holes in the universe. Future GW detectors will
greatly improve their sensitivity during the coming decade, as will
near-infrared telescopes capable of independently finding kilonovae from
neutron star mergers. However, the electromagnetic counterparts to
high-frequency (LIGO/Virgo band) GW sources will be distant and faint and thus
demand ELT capabilities for characterization. ELTs will be important and
necessary contributors to an advanced and complete multi-messenger network.Comment: White paper submitted to the Astro2020 Decadal Surve
SN 2022jox: An extraordinarily ordinary Type II SN with Flash Spectroscopy
We present high cadence optical and ultraviolet observations of the Type II
supernova (SN), SN 2022jox which exhibits early spectroscopic high ionization
flash features of \ion{H}{1}, \ion{He}{2}, \ion{C}{4}, and \ion{N}{4} that
disappear within the first few days after explosion. SN 2022jox was discovered
by the Distance Less than 40 Mpc (DLT40) survey 0.75 days after explosion
with followup spectra and UV photometry obtained within minutes of discovery.
The SN reached a peak brightness of M 17.3 mag, and has an
estimated Ni mass of 0.04 M, typical values for normal Type II
SNe. The modeling of the early lightcurve and the strong flash signatures
present in the optical spectra indicate interaction with circumstellar material
(CSM) created from a progenitor with a mass loss rate of . There may also be some indication
of late-time CSM interaction in the form of an emission line blueward of
H seen in spectra around 200 days. The mass-loss rate is much higher
than the values typically associated with quiescent mass loss from red
supergiants, the known progenitors of Type II SNe, but is comparable to
inferred values from similar core collapse SNe with flash features, suggesting
an eruptive event or a superwind in the progenitor in the months or years
before explosion.Comment: Submitted to Ap
The blue supergiant progenitor of the Supernova Imposter at 2019krl
Extensive archival Hubble Space Telescope, Spitzer Space Telescope, and Large Binocular Telescope imaging of the recent intermediate-luminosity transient, AT 2019krl in M74, reveal a bright optical and mid-infrared progenitor star. While the optical peak of the event was missed, a peak was detected in the infrared with an absolute magnitude of M 4.5 μm = -18.4 mag, leading us to infer a visual-wavelength peak absolute magnitude of -13.5 to -14.5. The pre-discovery light curve indicated no outbursts over the previous 16 yr. The colors, magnitudes, and inferred temperatures of the progenitor best match a 13-14 M o˙ yellow or blue supergiant (BSG) if only foreground extinction is taken into account, or a hotter and more massive star if any additional local extinction is included. A pre-eruption spectrum of the star reveals strong Hα and [N ii] emission with wings extending to 2000 km s-1. The post-eruption spectrum is fairly flat and featureless with only Hα, Na i D, [Ca ii], and the Ca ii triplet in emission. As in many previous intermediate-luminosity transients, AT 2019krl shows remarkable observational similarities to luminous blue variable (LBV) giant eruptions, SN 2008S-like events, and massive-star mergers. However, the information about the pre-eruption star favors either a relatively unobscured BSG or a more extinguished LBV with M > 20 Mo˙ likely viewed pole-on.Fil: Andrews, Jennifer E.. University of Arizona; Estados UnidosFil: Jencson, Jacob E.. University of Arizona; Estados UnidosFil: Van Dyk, Schuyler D.. Spitzer Science Center; Estados UnidosFil: Smith, Nathan. University of Arizona; Estados UnidosFil: Neustadt, Jack M. M.. Ohio State University; Estados UnidosFil: Sand, David J.. University of Arizona; Estados UnidosFil: Kreckel, K.. Astronomisches Rechen-institut Heidelberg; AlemaniaFil: Kochanek, C.S.. Ohio State University; Estados UnidosFil: Valenti, S.. University of California at Davis; Estados UnidosFil: Strader, Jay. Michigan State University; Estados UnidosFil: Bersten, Melina Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Blanc, Guillermo A.. Universidad de Chile; ChileFil: Bostroem, K. Azalee. University of California at Davis; Estados UnidosFil: Brink, Thomas G.. University of California at Berkeley; Estados UnidosFil: Emsellem, Eric. European Southern Observatory; AlemaniaFil: Filippenko, Alexei V.. University of California at Berkeley; Estados UnidosFil: Folatelli, Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Kasliwal, Mansi. California Institute of Technology; Estados UnidosFil: Masci, Frank J.. Spitzer Science Center; Estados UnidosFil: McElroy, Rebecca. The University Of Sydney; AustraliaFil: Milisavljevic, Dan. Purdue University; Estados UnidosFil: Santoro, Francesco. Max Planck Institut für Astronomie; AlemaniaFil: Szalai, Tamás. University of Szeged; Hungrí
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