VHE Gamma-Ray Emission from H1722+119

H1722+119 is a BL Lac object, that was listed as candidate TeV blazar in Costamante & Ghisellini (2002) based on its X-ray and radio properties. Its redshift is uncertain; Sbarufatti et al. 2006 give z>0.17. The source has been detected by Fermi-LAT, in the Second Fermi Catalogue with F(>1 GeV) (3.7+-0.3)e-09 cm^-2 s^-1 and with spectral index 1.92+-0.06.

H1722+119 was observed for five nights by the MAGIC telescopes starting May 17th 2013 and collecting 11 hours of good quality data. A preliminary analysis yields a detection of the source with a statistical significance of more than 5 standard deviations. The VHE flux of this detection is about 2% of the flux from the Crab nebula above 140 GeV. The previous VHE gamma-ray observations of the source produced an upper limit of 4.2% Crab nebula flux above 140 GeV (Aleksic et al. 2011).

The MAGIC observations were triggered by the extended optical high state of the source, reported by the Tuorla blazar monitoring program (http://users.utu.fi/kani/1m). At the beginning of May 2013 the source reached an R-band magnitude of 14.65, the brightest ever observed since 2005, when the monitoring started. We also analyzed the Fermi-LAT data, finding indication of a spectral index harder than reported in the Second Fermi Catalog. A Swift-XRT ToO observation was performed on 20th May.

MAGIC will continue the observations of the source as soon as the moon conditions allow it again and multiwavelength observations are encouraged.

The MAGIC contact persons for these observations are J. Cortina (cortina@ifae.es) and E. Lindfors (elilin@utu.fi).

MAGIC is a system of two 17m-diameter Imaging Atmospheric Cherenkov Telescopes located at the Canary island of La Palma, Spain, and designed to perform gamma-ray astronomy in the energy range from 50 GeV to greater than 20 TeV. 

http://www.astronomerstelegram.org/?read=5080

Inflationary paradigm in trouble after Planck2013

The recent Planck satellite combined with earlier results eliminate a wide spectrum of more complex inflationary models and favour models with a single scalar field, as reported in the analysis of the collaboration. More important, though, is that all the simplest inflation models are disfavoured by the data while the surviving models -- namely, those with plateau-like potentials -- are problematic. We discuss how the restriction to plateau-like models leads to three independent problems: it exacerbates both the initial conditions problem and the multiverse-unpredictability problem and it creates a new difficulty which we call the inflationary "unlikeliness problem." Finally, we comment on problems reconciling inflation with a standard model Higgs, as suggested by recent LHC results. In sum, we find that recent experimental data disfavours all the best-motivated inflationary scenarios and introduces new, serious difficulties that cut to the core of the inflationary paradigm. Forthcoming searches for B-modes, non-Gaussianity and new particles should be decisive. 

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arXiv.org > astro-ph > arXiv:1304.2785

VHE Gamma-Ray Emission from MS1221.8+2452

The MAGIC collaboration reports the discovery of very high energy (VHE; E>100 GeV) gamma-ray emission from MS1221.8+2452 (12h24m24.2s +24d36m24s, J2000.0). MS1221.8+2452 is a blazar located at a redshift of 0.218 (Sbarufatti et al., 2005, ApJ 635, 173) and classified as a high synchrotron peaked (HSP) BL Lac. It is one of the very few BL Lacs that has been imaged with the Hubble Space Telescope (Jannuzzi et al., 1997, ApJ 491, 146). It has been included in the ROSAT Bright Source Catalog (Voges et al., 1999, A&A 349, 389) and identified as XBL (X-Ray-Selected BL Lac) by the Einstein Extended Medium Sensitivity Survey (Rector et al. 2000, AJ 120, 1626). 

The object was observed with the MAGIC telescopes for 4 hours from 2013/04/30 to 2013/05/01. The preliminary analysis of these data resulted in the detection of MS1221.8+2452 with a statistical significance of more than 5 standard deviations. The VHE flux of this detection was estimated to be about 4% of the Crab nebula flux above 200 GeV.

MS1221.8+2452 was observed with Swift during March and April 2013, showing flux variability ranging from 3e-12 erg/cm2/s to 13e-12 erg/cm2/s in the 0.3-10 keV energy range. This source was flagged as a promising VHE source candidate by the Fermi-LAT collaboration, information that was shared with the MAGIC collaboration (as well as other ground-based gamma-ray instruments).

MAGIC observations on MS1221.8+2452 will continue during the next days until 2013/05/12 and multiwavelength observations are encouraged.

The MAGIC contact persons for these observations are J. Cortina (cortina@ifae.es) and F. Borracci (frabor@mpp.mpg.de).

MAGIC is a system of two 17m-diameter Imaging Atmospheric Cherenkov Telescopes located at the Canary island of La Palma, Spain, and designed to perform gamma-ray astronomy in the energy range from 50 GeV to greater than 20 TeV. 

Link: http://www.astronomerstelegram.org/?read=5038

Birth Of A Black Hole

When a massive star exhausts its fuel, it collapses under its own gravity and produces a black hole, an object so dense that not even light can escape its gravitational grip. According to a new analysis by an astrophysicist at the California Institute of Technology (Caltech), just before the black hole forms, the dying star may generate a distinct burst of light that will allow astronomers to witness the birth of a new black hole for the first time.

Tony Piro, a postdoctoral scholar at Caltech, describes this signature light burst in a paper published in the May 1 issue of the Astrophysical Journal Letters. While some dying stars that result in black holes explode as gamma-ray bursts, which are among the most energetic phenomena in the universe, those cases are rare, requiring exotic circumstances, Piro explains. “We don’t think most run-of-the-mill black holes are created that way.” In most cases, according to one hypothesis, a dying star produces a black hole without a bang or a flash: the star would seemingly vanish from the sky—an event dubbed an unnova. “You don’t see a burst,” he says. “You see a disappearance.” ......

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Birth Of A Black Hole

Shockingly bright burst

A record-setting blast of gamma rays from a dying star in a distant galaxy has wowed astronomers around the world. The eruption, which is classified as a gamma-ray burst, or GRB, and designated GRB 130427A, produced the highest-energy light ever detected from such an event.

"We have waited a long time for a gamma-ray burst this shockingly, eye-wateringly bright," said Julie McEnery, project scientist for the Fermi Gamma-ray Space Telescope at NASA's Goddard Space Flight Center in Greenbelt, Md. "The GRB lasted so long that a record number of telescopes on the ground were able to catch it while space-based observations were still ongoing."

Just after 3:47 a.m. EDT on Saturday, April 27, Fermi's Gamma-ray Burst Monitor (GBM) triggered on eruption of high-energy light in the constellation Leo. The burst occurred as NASA's Swift satellite was slewing between targets, which delayed its Burst Alert Telescope's detection by a few seconds.....

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NASA's Fermi, Swift see 'shockingly bright' burst