Implementation of Robust Image Artifact Removal in SWarp through Clipped Mean Stacking

Seitz, Steven M.; Bernstein, G. M.

doi:10.1086/675080

Cited by 38 publications

(31 citation statements)

References 22 publications

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“…The full set of light curves are shown as grey lines in the background, and each panel highlights an individual filter in black. We correct for Galactic extinction using the attenuation curve from Fitzpatrick (1999) and EB−V = AV /RV = 0.01 for RV = 3.1 and AV = 0.029 (Schlafly & Finkbeiner 2011). weighted coaddition of 298 R-band and 69 g-band images from PTF/iPTF taken between 2009 and 2016 using the CLIPPED combine strategy in SWarp (Bertin 2010;Gruen et al 2014). PTF/iPTF images were used instead of ZTF images to build references as they were obtained years prior to the transient, and thus less likely to contain any transient flux.…”

Section: Search For Pre-discovery Emissionmentioning

confidence: 99%

Evidence for Late-stage Eruptive Mass Loss in the Progenitor to SN2018gep, a Broad-lined Ic Supernova: Pre-explosion Emission and a Rapidly Rising Luminous Transient

Goldstein

Schulze

et al. 2019

ApJ

106

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We present detailed observations of ZTF18abukavn (SN2018gep), discovered in high-cadence data from the Zwicky Transient Facility as a rapidly rising (1.4 ± 0.1 mag/hr) and luminous (M g,peak = −20 mag) transient. It is spectroscopically classified as a broad-lined stripped-envelope supernova (Ic-BL SN). The high peak luminosity (L bol 3×10 44 erg s −1 ), the short rise time (t rise = 3 day in g-band), and the blue colors at peak (g −r ∼ −0.4) all resemble the high-redshift Ic-BL iPTF16asu, as well as several other unclassified fast transients. The early discovery of SN2018gep (within an hour of shock breakout) enabled an intensive spectroscopic campaign, including the highest-temperature (T eff 40, 000K) arXiv:1904.11009v4 [astro-ph.HE] 1 Dec 2019 2 spectra of a stripped-envelope SN. A retrospective search revealed luminous (M g ∼ M r ≈ −14 mag) emission in the days to weeks before explosion, the first definitive detection of precursor emission for a Ic-BL. We find a limit on the isotropic gamma-ray energy release E γ,iso < 4.9 × 10 48 erg, a limit on X-ray emission L X < 10 40 erg s −1 , and a limit on radio emission νL ν 10 37 erg s −1 . Taken together, we find that the early (< 10 day) data are best explained by shock breakout in a massive shell of dense circumstellar material (0.02 M ) at large radii (3 × 10 14 cm) that was ejected in eruptive pre-explosion mass-loss episodes. The late-time (> 10 day) light curve requires an additional energy source, which could be the radioactive decay of Ni-56.

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Section: Search For Pre-discovery Emissionmentioning

confidence: 99%

Evidence for Late-stage Eruptive Mass Loss in the Progenitor to SN2018gep, a Broad-lined Ic Supernova: Pre-explosion Emission and a Rapidly Rising Luminous Transient

Goldstein

Schulze

et al. 2019

ApJ

106

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“…4.2. For this step we obtained the 36 image stacks by using the named clipped-mean algorithm described in Gruen et al (2014) and implemented in SWarp. This algorithm has been specifically designed for rejecting artefacts present in individual contributors to resulting stacks.…”

Section: Image Coadditionmentioning

confidence: 99%

The OTELO survey

Bongiovanni

Ramón-Pérez

García

et al. 2019

A&A

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Context. The evolution of galaxies through cosmic time is studied observationally by means of extragalactic surveys. The usefulness of these surveys is greatly improved by increasing the cosmological volume, in either depth or area, and by observing the same targets in different wavelength ranges. A multi-wavelength approach using different observational techniques can compensate for observational biases. Aims. The OTELO survey aims to provide the deepest narrow-band survey to date in terms of minimum detectable flux and emission line equivalent width in order to detect the faintest extragalactic emission line systems. In this way, OTELO data will complements other broad-band, narrow-band, and spectroscopic surveys. Methods. The red tunable filter of the OSIRIS instrument on the 10.4 m Gran Telescopio Canarias (GTC) is used to scan a spectral window centred at 9175 Å, which is free from strong sky emission lines, with a sampling interval of 6 Å and a bandwidth of 12 Å in the most deeply explored EGS region. Careful data reduction using improved techniques for sky ring subtraction, accurate astrometry, photometric calibration, and source extraction enables us to compile the OTELO catalogue. This catalogue is complemented with ancillary data ranging from deep X-ray to far-infrared, including high resolution HST images, which allow us to segregate the different types of targets, derive precise photometric redshifts, and obtain the morphological classification of the extragalactic objects detected. Results. The OTELO multi-wavelength catalogue contains 11 237 entries and is 50% complete at AB magnitude 26.38. Of these sources, 6600 have photometric redshifts with an uncertainty δ zphot better than 0.2 (1+zphot). A total of 4336 of these sources correspond to preliminary emission line candidates, which are complemented by 81 candidate stars and 483 sources that qualify as absorption line systems. The OTELO survey results will be released to the public on the second half of 2019.

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“…van Dokkum 2001) or averaging over multiple exposures (e.g. Gruen et al 2014;Desai et al 2016) to sparsity-based signal reconstructions (e.g. Rassat et al 2013;Wallis et al 2017).…”

Section: Missing Datamentioning

confidence: 99%

Spatial field reconstruction with INLA: application to IFU galaxy data

González–Gaitán

Krone-Martins

Cameron

et al. 2018

Monthly Notices of the Royal Astronomical Society

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Astronomical observations of extended sources, such as cubes of integral field spectroscopy (IFS), encode auto-correlated spatial structures that cannot be optimally exploited by standard methodologies. This work introduces a novel technique to model IFS datasets, which treats the observed galaxy properties as realizations of an unobserved Gaussian Markov random field. The method is computationally efficient, resilient to the presence of low-signal-to-noise regions, and uses an alternative to Markov Chain Monte Carlo for fast Bayesian inference -the Integrated Nested Laplace Approximation (INLA). As a case study, we analyse 721 IFS data cubes of nearby galaxies from the CALIFA and PISCO surveys, for which we retrieve the maps of the following physical properties: age, metallicity, mass and extinction. The proposed Bayesian approach, built on a generative representation of the galaxy properties, enables the creation of synthetic images, recovery of areas with bad pixels, and an increased power to detect structures in datasets subject to substantial noise and/or sparsity of sampling. A snippet code to reproduce the analysis of this paper is available in the COIN toolbox, together with the field reconstructions of the CALIFA and PISCO samples.

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Implementation of Robust Image Artifact Removal in SWarp through Clipped Mean Stacking

Cited by 38 publications

References 22 publications

Evidence for Late-stage Eruptive Mass Loss in the Progenitor to SN2018gep, a Broad-lined Ic Supernova: Pre-explosion Emission and a Rapidly Rising Luminous Transient

Evidence for Late-stage Eruptive Mass Loss in the Progenitor to SN2018gep, a Broad-lined Ic Supernova: Pre-explosion Emission and a Rapidly Rising Luminous Transient

The OTELO survey

Spatial field reconstruction with INLA: application to IFU galaxy data

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