FRB 180916 is a most intriguing source capable of producing repeating fast radio bursts with a periodic 16.3 day temporal pattern. The source is well positioned in a star-forming region in the ...outskirts of a nearby galaxy at 150 Mpc distance. In this Letter we report on the X-ray and γ-ray observations of FRB 180916 obtained by AGILE and Swift. We focused especially on the recurrent 5 day time intervals of enhanced radio bursting. In particular, we report on the results obtained in the time intervals 2020 February 3-8, 2020 February 25, 2020 March 5-10, and 2020 March 22-28 during a multiwavelength campaign involving high-energy and radio observations of FRB 180916. We also searched for temporal coincidences at millisecond timescales between the 32 known radio bursts of FRB 180916 and X-ray and MeV events detectable by AGILE. We do not detect any simultaneous event or any extended X-ray and γ-ray emission on timescales of hours/days/weeks. Our cumulative X-ray (0.3-10 keV) flux upper limit of 5 × 10−14 erg cm−2 s−1 (obtained during 5 day active intervals from several 1-2 ks integrations) translates into an isotropic luminosity upper limit of LX,UL ∼ 1.5 × 1041 erg s−1. Deep γ-ray observations above 100 MeV over a many-year timescale provide an average luminosity upper limit one order of magnitude larger. These results provide the so-far most stringent upper limits on high-energy emission from the FRB 180916 source. Our results constrain the dissipation of magnetic energy from a magnetar-like source of radius Rm, internal magnetic field Bm, and dissipation timescale τd to satisfy the relation , where Rm,6 is Rm in units of 106 cm, Bm,16 is Bm in units of 1016 G, and τd,8 in units of 108 s.
Hard X-ray observations are crucial to study the non-thermal jet emission from high-redshift, powerful blazars. We observed two bright z > 2 flat-spectrum radio quasars (FSRQs) in hard X-rays to ...explore the details of their relativistic jets and their possible variability. S50014+81 (at z = 3.366) and B0222+185 (at z = 2.690) have been observed twice by the Nuclear Spectroscopic Telescope Array (NuSTAR) simultaneously with Swift X-ray Telescope, showing different variability behaviors. We found that NuSTAR is instrumental to explore the variability of powerful high-redshift blazars, even when no gamma-ray emission is detected. The two sources have proven to have respectively the most luminous accretion disc and the most powerful jet among known blazars. Thanks to these properties, they are located at the extreme end of the jet-accretion disc relation previously found for gamma-ray detected blazars, to which they are consistent.
We present a detailed X-ray spectral analysis of the nearby Seyfert 2 galaxy MCG-01-24-12 based on a multi-epoch data set. Data were obtained with different X-ray satellites, namely
XMM-Newton
,
...NuSTAR
,
Swift
, and
Chandra
, and cover different time intervals, from a few days to years. From 2006 to 2013 the source had a 2–10 keV flux of ∼1.5 × 10
−11
erg cm
−2
s
−1
, consistent with archival observations based on HEAO and
Beppo
SAX data, though a 2019
Chandra
snapshot caught the source in an extreme low flux state a factor of ∼10 fainter than its historical level. Based on phenomenological and physically motivated models, we find the X-ray spectrum of MCG-01-24-12 to be best modelled by a power-law continuum emission with Γ = 1.76 ± 0.09 with a high energy cut-off at
E
c
= 70
−14
+21
keV that is absorbed by a fairly constant column density of
N
H
= (6.3 ± 0.5) × 10
22
cm
−2
. These quantities allowed us to estimate the properties of the hot corona in MCG-01-24-12 for the cases of a spherical or slab-like hot Comptonising plasma to be
kT
e
= 27
−4
+8
keV,
τ
e
= 5.5 ± 1.3 and
kT
e
= 28
−5
+7
keV,
τ
= 3.2 ± 0.8, respectively. Finally, despite the short duration of the exposures, possible evidence of the presence of outflows is discussed.
During its first observing run, in late 2015, the advanced Laser Interferometer Gravitational-wave Observatory facility announced three gravitational wave (GW) triggers to electromagnetic follow-up ...partners. Two of these have since been confirmed as being of astrophysical origin: both are binary black hole mergers at ∼500 Mpc; the other trigger was later found not to be astrophysical. In this paper, we report on the Swift follow-up observations of the second and third triggers, including details of 21 X-ray sources detected; none of which can be associated with the GW event. We also consider the challenges that the next GW observing run will bring as the sensitivity and hence typical distance of GW events will increase. We discuss how to effectively use galaxy catalogues to prioritize areas for follow-up, especially in the presence of distance estimates from the GW data. We also consider two galaxy catalogues and suggest that the high completeness at larger distances of the 2MASS Photometric Redshift catalogue makes it very well suited to optimize Swift follow-up observations.
Aims.
Fast radio bursts are bright radio transients whose origins are not yet understood. The search for a multi-wavelength counterpart of those events can set a tight constraint on the emission ...mechanism and the progenitor source.
Methods.
We conducted a multi-wavelength observational campaign on FRB 20180916B between October 2020 and August 2021 over eight activity cycles of the source. Observations were carried out in the radio band by the SRT both at 336 and 1547 MHz and the uGMRT at 400 MHz. Simultaneous observations were conducted by the optical telescopes Asiago (
Galileo
and
Copernico
), CMO SAI MSU, CAHA 2.2 m, RTT-150 and TNG, and X/
γ
-ray detectors on board the AGILE,
Insight–
HXMT, INTEGRAL, and
Swift
satellites.
Results.
We present the detection of 14 new radio bursts detected with the SRT at 336 MHz and seven new bursts with the uGMRT from this source. We provide the deepest prompt upper limits in the optical band for FRB 20180916B to date. In fact, the TNG/SiFAP2 observation simultaneous to a burst detection by uGMRT gives an upper limit
E
optical
/
E
radio
< 1.3 × 10
2
. Another burst detected by the SRT at 336 MHz was also co-observed by
Insight–
HXMT. The non-detection in the X-rays yields an upper limit (1 − 30 keV band) of
E
X − ray
/
E
radio
in the range of (0.9 − 1.3) × 10
7
, depending on the model that is considered for the X-ray emission.
Previous studies have found that expression of the Glucocorticoid Receptor (GR) is altered or reduced in various cancers, while the GR promoter has been shown to be methylated in gastric, lung, and ...colorectal cancers. Examining a small cohort of matched normal and breast cancer samples we found that GR levels were dramatically reduced in almost all tumors in relation to their normal tissue. The methylation status of the GR promoter was assessed to determine if this observed decrease of expression in breast tumors could be due to epigenetic regulation. While it was not methylated in normal tissue, the GR proximal promoter was methylated in 15% of tumor samples, particularly, but not exclusively, in Estrogen Receptor positive tumors. GR expression in these tumors was particularly low and loss of GR expression was specifically correlated with methylation of the proximal promoter GR B region. Overall, these results show that hypermethylation of the promoter in tumors is a frequent event and suggests that GR may act as a tumor suppressor in breast tissue.
Context. The Swift satellite is a multi-wavelength observatory specifically designed for gamma-ray burst (GRB) astronomy that is operational since 2004. Swift is also a very flexible multi-purpose ...facility that supports a wide range of scientific fields such as active galactic nuclei, supernovae, cataclysmic variables, Galactic transients, active stars and comets. The Swift X-ray Telescope (XRT) has collected more than 150 Ms of observations in its first seven years of operations. Aims. The purpose of this work is to present to the scientific community the list of all the X-ray point sources detected in XRT imaging data taken in photon counting mode during the first seven years of Swift operations. All these point-like sources, excluding the GRB, will be stored in a catalog publicly available (1SWXRT). Methods. We considered all the XRT observations with exposure time longer than 500 s taken in the period 2005−2011. Data were reduced and analyzed with standard techniques and a list of detected sources for each observation was produced. A careful visual inspection was performed to remove extended, spurious and piled-up sources. Finally, positions, count rates, fluxes, and the corresponding uncertainties were computed. Results. We have analyzed more than 35 000 XRT fields, with exposures ranging between 500 s and 100 ks, for a total exposure time of almost 140 Ms. The catalog includes approximately 89 000 entries, of which almost 85 000 are not affected by pile-up and are not GRBs. Considering that many XRT fields were observed several times, we have a total of ~36 000 distinct celestial sources. We computed count rates in three energy bands: 0.3−10 keV (Full, or F), 0.3−3 keV (Soft, or S) and 2−10 keV (Hard, or H). Each entry has a detection in at least one of these bands. In particular, we detect ~80 000, ~70 000 and ~25 500 in the F, S and H band, respectively. Count rates were converted into fluxes in the 0.5−10, 0.5−2 and 2−10 keV bands. The flux interval sampled by the detected sources is 7.4 × 10-15 − 9.1 × 10-11, 3.1 × 10-15 − 1.1 × 10-11 and 1.3 × 10-14 − 9.1 × 10-11 erg cm-2 s-1 for the F, S and H band, respectively. Some possible scientific uses of the catalog are also highlighted.
The aim of the study was to examine the need for modified safety planning strategies in response to COVID-19–related increases in intimate partner violence (IPV) as the initial phase of adapting an ...IPV safety planning intervention in Toronto, Ontario.
A rapid, systematic review was conducted to elucidate existing safety planning strategies used during public health emergencies. These were supplemented with strategies from an expert panel. A survey of IPV survivors and service providers gauged the helpfulness of each strategy during COVID-19.
Together, the systematic review and expert panel yielded 26 conceptually distinct strategies, which were evaluated by 111 IPV survivors and providers. Of these, 19 (69%) were ‘highly recommended’, 3 (12%) were ‘somewhat recommended’ and 6 (23%) were not recommended for use during the COVID-19 pandemic because they might make the violence worse.
Safety planning needs have changed owing to the effect of COVID-19 on IPV incidence, service provision and risk factors, as well as policies restricting freedom of movement. These results will be used to modify an existing IPV safety planning mobile application for use during COVID-19 and future public health emergencies.
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