Context. Both multi-messenger astronomy and new high-throughput wide-field surveys require flexible tools for the selection and analysis of astrophysical transients. Aims. Here we introduce the alert ...management, photometry, and evaluation of light curves (AMPEL) system, an analysis framework designed for high-throughput surveys and suited for streamed data. AMPEL combines the functionality of an alert broker with a generic framework capable of hosting user-contributed code; it encourages provenance and keeps track of the varying information states that a transient displays. The latter concept includes information gathered over time and data policies such as access or calibration levels. Methods. We describe a novel ongoing real-time multi-messenger analysis using AMPEL to combine IceCube neutrino data with the alert streams of the Zwicky Transient Facility (ZTF). We also reprocess the first four months of ZTF public alerts, and compare the yields of more than 200 different transient selection functions to quantify efficiencies for selecting Type Ia supernovae that were reported to the Transient Name Server (TNS). Results. We highlight three channels suitable for (1) the collection of a complete sample of extragalactic transients, (2) immediate follow-up of nearby transients, and (3) follow-up campaigns targeting young, extragalactic transients. We confirm ZTF completeness in that all TNS supernovae positioned on active CCD regions were detected. Conclusions. AMPEL can assist in filtering transients in real time, running alert reaction simulations, the reprocessing of full datasets as well as in the final scientific analysis of transient data. This is made possible by a novel way of capturing transient information through sequences of evolving states, and interfaces that allow new code to be natively applied to a full stream of alerts. This text also introduces a method by which users can design their own channels for inclusion in the AMPEL live instance that parses the ZTF stream and the real-time submission of high-quality extragalactic supernova candidates to the TNS.
Exposure-time Correction for the ZTF Camera Giomi, M.; Smith, R. M.; Kupfer, T. ...
Publications of the Astronomical Society of the Pacific,
03/2019, Letnik:
131, Številka:
997
Journal Article
Recenzirano
A correction factor is derived to account for nonuniformities in the exposure time as seen by different positions on the focal plane of the ZTF camera. These nonuniformities arise from a combination ...of the shutter opening and closing motion; the geometrical setup of the telescope; and the presence of obstructions in the beam beyond the pupil plane. The correction to the exposure time is measured by comparing a set of dome-flat images taken with multiple shutter opening/closing motions to those obtained with a normal exposure of the same total duration. The correction to the exposure time is small, of the order of 30 ms averaged over the entire field of view with peaks of ∼60 ms at the east and west edges of the camera. The effect is thus of the order of 0.1% on average for the nominal ZTF survey exposures of 30 s. Comparing the results obtained from three sets of dedicated observations acquired in 2017 December, we assess the stability of the correction factor to be better than 7% both in time and with respect to variations of the experimental conditions.
Verbena and lemon verbena aqueous preparations were investigated for their content of constituents, especially polyphenols by HPLC/DAD/ESI/MS analysis because they are used worldwide as herbal teas. ...The main class of compounds of these plants were phenylpropanoids (from 16 to 120
mg/g of dried extract), being verbascoside the most abundant in all the preparations up to 97% of the total phenylpropanoids. Also iridoids, hastatoside and verbenalin together with flavonoids, mono- and di-glucuronidic derivatives of luteolin and apigenin were found. These simple preparations, especially that obtained from infusion of lemon verbena, could be lyophilized to obtain a powder having interesting technological properties to be used as ingredients of cosmetics, food supplements and herbal medicinal products do to the many biological properties of verbascoside. In addition, the antioxidant property of the lemon verbena infusion was evaluated by the DPPH test using Trolox as the reference compound.
ABSTRACT MeV blazars are a sub-population of the blazar family, exhibiting larger-than-average jet powers, accretion luminosities, and black hole masses. Because of their extremely hard X-ray ...continua, these objects are best studied in the X-ray domain. Here, we report on the discovery by the Fermi Large Area Telescope and subsequent follow-up observations with NuSTAR, Swift, and GROND of a new member of the MeV blazar family: PMN J0641−0320. Our optical spectroscopy provides confirmation that this is a flat-spectrum radio quasar located at a redshift of z = 1.196. Its very hard NuSTAR spectrum (power-law photon index of ∼1 up to ∼80 keV) indicates that the emission is produced via inverse Compton scattering off of photons coming from outside the jet. The overall spectral energy distribution of PMN J0641−0320 is typical of powerful blazars and, using a simple one-zone leptonic emission model, we infer that the emission region is located either inside the broad line region or within the dusty torus.
Fusarium verticillioides
and
F. graminearum
cause ear rots in maize (
Zea mays
L.) that reduce yield and contaminate the grain with mycotoxins produced by the fungi. To map QTLs for resistance to ...these ear rots, a F
5
mapping population, consisting of 298 recombinant inbreds obtained by randomly selfing of the cross between LP4637 (moderately resistant) and L4674 (susceptible), was genotyped with 250 single nucleotide polymorphism markers and phenotyped 2 years for disease severity after silk inoculation with conidial suspensions of
F. verticillioides
and
F. graminearum
. Four QTLs were mapped in chromosomes 2, 3 and 5, bins 2.03, 3.05, 3.07 and 5.07, explaining ranges of 11.2–11.8, 3.4–5.1, 6.2–7.6 and 3.8–5.0 of phenotypic variances (%), respectively, depending on year and fungus. Additive effects of each QTL ranged from 5.0 to 11.9 % of ear area covered by mold and no epistatic interactions were observed. The four QTLs were effective for both
Fusarium
species and environments indicating that LP4637 is a source of broad resistance to
Fusarium
stable across environments. These results are consistent with previous research reporting QTLs for ear rot resistance in the same chromosome regions from sources of resistance growing in North America, Africa, Europe and China.
Exposure-time Correction for the ZTF Camera Giomi, M.; Smith, R. M.; Kupfer, T. ...
Publications of the Astronomical Society of the Pacific,
03/2019, Letnik:
131, Številka:
997
Journal Article
Recenzirano
A correction factor is derived to account for nonuniformities in the exposure time as seen by different positions on the focal plane of the ZTF camera. These nonuniformities arise from a combination ...of the shutter opening and closing motion; the geometrical setup of the telescope; and the presence of obstructions in the beam beyond the pupil plane. The correction to the exposure time is measured by comparing a set of dome-flat images taken with multiple shutter opening/closing motions to those obtained with a normal exposure of the same total duration. The correction to the exposure time is small, of the order of 30 ms averaged over the entire field of view with peaks of ∼60 ms at the east and west edges of the camera. The effect is thus of the order of 0.1% on average for the nominal ZTF survey exposures of 30 s. Comparing the results obtained from three sets of dedicated observations acquired in 2017 December, we assess the stability of the correction factor to be better than 7% both in time and with respect to variations of the experimental conditions.
Context.
Supernovae (SNe) Type Ibn are rapidly evolving and bright (
M
R, peak
∼ −19) transients interacting with He-rich circumstellar material (CSM). SN 2018bcc, detected by the ZTF shortly after ...explosion, provides the best constraints on the shape of the rising light curve (LC) of a fast Type Ibn.
Aims.
We used the high-quality data set of SN 2018bcc to study observational signatures of the class. Additionally, the powering mechanism of SN 2018bcc offers insights into the debated progenitor connection of Type Ibn SNe.
Methods.
We compared well-constrained LC properties obtained from empirical models with the literature. We fit the pseudo-bolometric LC with semi-analytical models powered by radioactive decay and CSM interaction. Finally, we modeled the line profiles and emissivity of the prominent He
I
lines, in order to study the formation of P-Cygni profiles and to estimate CSM properties.
Results.
SN 2018bcc had a rise time to peak of the LC of 5.6
−0.1
+0.2
days in the restframe with a rising shape power-law index close to 2, and seems to be a typical rapidly evolving Type Ibn SN. The spectrum lacked signatures of SN-like ejecta and was dominated by over 15 He emission features at 20 days past peak, alongside Ca and Mg, all with
V
FWHM
∼ 2000 km s
−1
. The luminous and rapidly evolving LC could be powered by CSM interaction but not by the decay of radioactive
56
Ni. Modeling of the He
I
lines indicated a dense and optically thick CSM that can explain the P-Cygni profiles.
Conclusions.
Like other rapidly evolving Type Ibn SNe, SN 2018bcc is a luminous transient with a rapid rise to peak powered by shock interaction inside a dense and He-rich CSM. Its spectra do not support the existence of two Type Ibn spectral classes. We also note the remarkable observational match to pulsational pair instability SN models.
We present the second catalog of flaring gamma-ray sources (2FAV) detected with the Fermi All-sky Variability Analysis (FAVA), a tool that blindly searches for transients over the entire sky observed ...by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. With respect to the first FAVA catalog, this catalog benefits from a larger data set, the latest LAT data release (Pass 8), as well as from an improved analysis that includes likelihood techniques for a more precise localization of the transients. Applying this analysis to the first 7.4 years of Fermi observations, and in two separate energy bands 0.1-0.8 GeV and 0.8-300 GeV, a total of 4547 flares were detected with significance greater than (before trials), on the timescale of one week. Through spatial clustering of these flares, 518 variable gamma-ray sources were identified. Based on positional coincidence, likely counterparts have been found for 441 sources, mostly among the blazar class of active galactic nuclei. For 77 2FAV sources, no likely gamma-ray counterpart has been found. For each source in the catalog, we provide the time, location, and spectrum of each flaring episode. Studying the spectra of the flares, we observe a harder-when-brighter behavior for flares associated with blazars, with the exception of BL Lac flares detected in the low-energy band. The photon indexes of the flares are never significantly smaller than 1.5. For a leptonic model, and under the assumption of isotropy, this limit suggests that the spectrum of freshly accelerated electrons is never harder than .
Context. Supernovae (SNe) Type Ibn are rapidly evolving and bright (MR, peak ∼ −19) transients interacting with He-rich circumstellar material (CSM). SN 2018bcc, detected by the ZTF shortly after ...explosion, provides the best constraints on the shape of the rising light curve (LC) of a fast Type Ibn. Aims. We used the high-quality data set of SN 2018bcc to study observational signatures of the class. Additionally, the powering mechanism of SN 2018bcc offers insights into the debated progenitor connection of Type Ibn SNe. Methods. We compared well-constrained LC properties obtained from empirical models with the literature. We fit the pseudo-bolometric LC with semi-analytical models powered by radioactive decay and CSM interaction. Finally, we modeled the line profiles and emissivity of the prominent He I lines, in order to study the formation of P-Cygni profiles and to estimate CSM properties. Results. SN 2018bcc had a rise time to peak of the LC of 5.6−0.1+0.2 days in the restframe with a rising shape power-law index close to 2, and seems to be a typical rapidly evolving Type Ibn SN. The spectrum lacked signatures of SN-like ejecta and was dominated by over 15 He emission features at 20 days past peak, alongside Ca and Mg, all with VFWHM ∼ 2000 km s−1. The luminous and rapidly evolving LC could be powered by CSM interaction but not by the decay of radioactive 56Ni. Modeling of the He I lines indicated a dense and optically thick CSM that can explain the P-Cygni profiles. Conclusions. Like other rapidly evolving Type Ibn SNe, SN 2018bcc is a luminous transient with a rapid rise to peak powered by shock interaction inside a dense and He-rich CSM. Its spectra do not support the existence of two Type Ibn spectral classes. We also note the remarkable observational match to pulsational pair instability SN models.
We present evidence that human peripheral blood lymphocytes, free of contaminating monocytes, rapidly produce high levels of tumor necrosis factor (TNF) when stimulated with phorbol diester and ...calcium ionophore, and lower but significant levels of TNF when stimulated with mitogens. These two types of inducers act preferentially on T cells, both CD4+ and CD8+. NK cells produce TNF only when stimulated with phorbol diester and calcium ionophore, and they do so at a much lower level than T cells. The procedures used in the purification of lymphocytes and the differential ability to respond to various inducers allow us to exclude that monocytes or basophils contaminating the lymphocyte preparation participate in the production of TNF. In particular, LPS, a potent inducer of TNF production from monocytes, is unable to induce significant levels of TNF in the lymphocyte preparations. The TNF produced by lymphocytes has antigenic, physicochemical, and biochemical characteristics identical to those of the TNF produced by myeloid cell lines or monocytes upon stimulation with LPS. LT is also produced by lymphocyte preparations. Production of TNF and LT proteins in response to the different inducers is paralleled by accumulation of cytoplasmic TNF and LT mRNA. Both at mRNA and at protein levels, stimulation of T lymphocytes with phorbol diester and calcium ionophore preferentially induces TNF, whereas mitogen stimulation preferentially induces LT. Our data suggest that the TNF and LT genes, two closely linked genes encoding two partially homologous proteins with almost identical biological functions, are independently regulated in lymphocytes.
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