Deep observations of the globular cluster M15 with the MAGIC telescopes
MAGIC Collaboration, V. A. Acciari, S. Ansoldi, L. A. Antonelli, A. Arbet Engels, D. Baack, A. Babić, B. Banerjee, U. Barres de Almeida, J. A. Barrio, J. Becerr… 展开作者
MAGIC Collaboration, V. A. Acciari, S. Ansoldi, L. A. Antonelli, A. Arbet Engels, D. Baack, A. Babić, B. Banerjee, U. Barres de Almeida, J. A. Barrio, J. Becerra González, W. Bednarek, E. Bernardini, A. Berti, J. Besenrieder, W. Bhattacharyya, C. Bigongiari, A. Biland, O. Blanch, G. Bonnoli, G. Busetto, R. Carosi, G. Ceribella, S. Cikota, S. M. Colak, P. Colin, E. Colombo, J. L. Contreras, J. Cortina, S. Covino, V. D'Elia, P. Da Vela, F. Dazzi, A. De Angelis, B. De Lotto, M. Delfino, J. Delgado, F. Di Pierro, E. Do Souto Espiñera, A. Domínguez, D. Dominis Prester, D. Dorner, M. Doro, S. Einecke, D. Elsaesser, V. Fallah Ramazani, A. Fattorini, A. Fernández-Barral, G. Ferrara, D. Fidalgo, L. Foffano, M. V. Fonseca, L. Font, C. Fruck, D. Galindo, S. Gallozzi, R. J. García López, M. Garczarczyk, S. Gasparyan, M. Gaug, P. Giammaria, N. Godinović, D. Green, D. Guberman, D. Hadasch, A. Hahn, J. Herrera, J. Hoang, D. Hrupec, S. Inoue, K. Ishio, Y. Iwamura, H. Kubo, J. Kushida, D. Kuveždić, A. Lamastra, D. Lelas, F. Leone, E. Lindfors, S. Lombardi, F. Longo, M. López, A. López-Oramas, B. Machado de Oliveira Fraga, C. Maggio, P. Majumdar, M. Makariev, M. Mallamaci, G. Maneva, M. Manganaro, K. Mannheim, L. Maraschi, M. Mariotti, M. Martínez, S. Masuda, D. Mazin, M. Minev, J. M. Miranda, R. Mirzoyan, E. Molina, A. Moralejo, V. Moreno, E. Moretti, P. Munar-Adrover, V. Neustroev, A. Niedzwiecki, M. Nievas Rosillo, C. Nigro, K. Nilsson, D. Ninci, K. Nishijima, K. Noda, L. Nogués, M. Nöthe, S. Paiano, J. Palacio, D. Paneque, R. Paoletti, J. M. Paredes, G. Pedaletti, P. Peñil, M. Peresano, M. Persic, P. G. Prada Moroni, E. Prandini, I. Puljak, J. R. Garcia, W. Rhode, M. Ribó, J. Rico, C. Righi, A. Rugliancich, L. Saha, N. Sahakyan, T. Saito, K. Satalecka, T. Schweizer, J. Sitarek, I. Šnidarić, D. Sobczynska, A. Somero, A. Stamerra, M. Strzys, T. Surić, F. Tavecchio, P. Temnikov, T. Terzić, M. Teshima, N. Torres-Albà, S. Tsujimoto, J. van Scherpenberg, G. Vanzo, M. Vazquez Acosta, I. Vovk, M. Will, D. Zarić
备注：
11 pages, 7 figures, accepted for publication in MNRAS
发表信息：
Monthly Notices of the Royal Astronomical Society, Volume 484, Issue 2, 1 April 2019, Pages 2876-2885
A population of globular clusters (GCs) has been recently established by the Fermi-LAT telescope as a new class of GeV $γ$-ray sources. Leptons accelerated to TeV energies, in the inner magnetospheres of MSPs or in their wind regions, should produce $γ$-rays through the inverse Compton scattering in the dense radiation field from the huge population of stars. We have conducted deep observations of the globular cluster M15 with the MAGIC telescopes and used 165 hrs in order to search for $γ$-ray emission. A strong upper limit on the TeV $γ$-ray flux $<3.2\times 10^{-13}\mathrm{cm^{-2}s^{-1}}$ above 300 GeV ($<0.26\%$ of the Crab nebula flux) has been obtained. We interpret this limit as a constraint on the efficiency of the acceleration of leptons in the magnetospheres of the MSPs. We constrain the injection rate of relativistic leptons, $η_{\rm e}$, from the MSPs magnetospheres and their surrounding. We conclude that $η_{\rm e}$ must be lower than expected from the modelling of high energy processes in MSP inner magnetospheres. For leptons accelerated with the power law spectrum in the MSP wind regions, $η_{\rm e}$ is constrained to be much lower than derived for the wind regions around classical pulsars. These constraints are valid for the expected range of magnetic field strengths within the GC and for the range of likely energies of leptons injected from the inner magnetospheres, provided that the leptons are not removed from the globular cluster very efficiently due to advection process. We discuss consequences of these constraints for the models of radiation processes around millisecond pulsars.
Search for an extended emission around blazars with the MAGIC telescope
来自河外源的极高能量伽马射线可以与星系际辐射场相互作用。这个过程可能会导致电磁级联，其循环如下：产生电子-正电子对，然后由于逆康普顿散射产生次级伽马射线。由于电子和正电子在星系际磁场中会被散射，在某些条件下，它们的辐射可能会重新导向观测者。因此，我们可以预期，二次伽马射线发射可能会在源周围产生明显的扩展晕。MAGIC是一台成像大气切伦科夫望远镜，位于加那利群岛的拉帕尔马，Roque de los Muchachos天文台（2200 m.a.s.l）。利用MAGIC望远镜的专用蒙特卡罗模拟，研究了$1^\circ$直径范围内的各种源尺寸和扩展发射轮廓。我们目前的研究结果的一个可能的扩展发射Mrk 421和Mrk 501完成的MAGIC望远镜。
Overview of the results from extra-galactic observations with the MAGIC telescopes
活动星系核的非热喷流辐射在频率范围内有几个数量级。因此，观测方法需要多波长（MWL）活动，收集无线电，光学，紫外线，X射线，高能直到甚高能（VHE）伽马射线波段的数据。MAGIC是加那利群岛拉帕尔马Roque de los Muchachos天文台的一个由两台17米直径望远镜组成的系统，积极参与并组织MWL对已知和新发现的VHE源的观测。在这些会议记录中，我们报告了MAGIC河外观测的最新结果，该结果在时间变率研究和喷流排放模型方面获得了新的见解。
MAGIC is an instrument composed of a pair of telescopes for gamma- ray and cosmic-ray astrophysics in the TeV range. It is operating for more than a decade now, and is one of the current best performing instruments in this field, specifically at low energies, where it achieves the largest sensitivity. MAGIC pursues a strong program in galactic and extragalactic gamma-ray science. Its catalog of blazars, radiogalaxies and galaxy clusters observations as well as supernovae, novae, pulsar wind nebulae, pulsars and binary systems has now increased to several tens of detected targets. In addition, …
MAGIC has been exploring the sky at Very High Energy gamma-rays (50 GeV - 50 TeV) since 2004, operating first with a single telescope and from 2009 with two telescopes in stereoscopic mode. MAGIC has carried out a observational program involving fundamental physics and astrophysics topics. In this paper we present some of the most important results obtained by MAGIC, with a special emphasis in the most recent ones.
MAGIC is a stereoscopic system of two Imaging Atmospheric Cherenkov Telescopes operating in the very high energy (VHE) range from about 50 GeV to over 50 TeV. The VHE gamma-ray spectra measured at Earth carry an imprint of the extragalactic background light (EBL) and can be used to study the EBL density and its evolution in time. In the last few years, precision measurements of several blazars in the redshift range from z=0.03 up to z=0.9 were performed with MAGIC obtaining strong limits on the EBL density from single sources. In this paper, we present the results from a combined likelihood an…
MAGIC Telescopes observation of the BL Lac objects 1ES 1215+303 and 1ES 1218+304
两个BL Lac天体1 ES 1215+303和1 ES 1218+304，相隔0.8度，在2010-2011年用MAGIC切伦科夫望远镜观测到。2011年1月的观测结果是第一次探测到1 ES 1215+303（也称为ON-325）超过100 GeV，它在2010年10月被费米-LAT合作组织标记为有希望的甚高能（VHE，E > 100 GeV）伽马射线源候选者。2011年1月的观测是由Tuorla blazar监测计划报告的光源的高光学状态触发的。与2010年数据的比较表明，1 ES 1215+303也在VHE伽马射线中闪耀。此外，机会目标（ToO）的X射线观测表明，通量几乎是以前观测（2009年12月）的两倍。相反，1 ES 1218+304是一个众所周知的VHE伽马射线发射器，位于同一视场，然后与MAGIC同时观察。在这方面的贡献，我们提出了这两个VHE伽玛射线发射活动星系核的MAGIC观测的初步结果。
The improvement on the Imaging Air Cherenkov Technique (IACT) led to the discovery of a new type of sources that can emit at very high energies: the gamma-ray binaries. Only six systems are part of this exclusive class. We summarize the latest results from the observations performed with the MAGIC telescopes on different systems as the gamma-ray binary LS I +61$^{\circ}$ 303 and the microquasars SS433, V404 Cygni and Cygnus X-1, which are considered potential VHE gamma-ray emitters. The binary system LS I +61$^{\circ}$ 303 has been observed by MAGIC in a long-term monitoring campaign. We show …
Globular clusters are known to host an unusually large population of millisecond pulsar when compared to the Galactic disk. This is thanks to the high rate of dynamical encounters occurring in the clusters that can create the conditions to efficiently recycle neutron stars into millisecond pulsars. The result is a rich population of pulsars with properties and companions difficult or impossible to replicate in the Galactic disk. For these reasons, globular clusters have been and still are a prime target of searches for new and exciting pulsars. Because of their large distances, the limiting fa…
Detection of LS I +61 303 in a low VHE gamma-ray emission state with the MAGIC telescopes
在过去的几年里，MAGIC望远镜在VHE伽马射线中对伽马射线双星系统LS I +61 303进行了非常详细的研究。2005年9月至2008年1月期间，该系统的VHE发射在轨道相位0.6-0.7处表现出明显的周期性爆发。在2008年秋季，费米合作组也报告了MeV到GeV能量范围内的周期性发射，但在相位0.35-0.45之间有一个偏移的爆发。MAGIC在2009年再次观测到LS I+61 303，使用了两倍灵敏度的立体模式，以进行VHE伽马射线和费米/LAT能带之间的详细相关研究。在这里，我们提出了我们的新的结果，这表明在VHE伽马射线通量的周期性爆发的阶段，几乎一个数量级相比，我们以前的测量显着减少。此外，0.1相平均光变曲线显示没有显著的爆发，而是相当恒定的通量。在这里，我们将讨论我们的结果对未来的LS I +61 303的伽马射线研究的影响。
The MAGIC telescopes, located at the Roque de los Muchachos Observatory (2200 a.s.l.) in the Canary Island of La Palma, are placed on the top of a mountain, from where a window of visibility of about 5 deg in zenith and 80 deg in azimuth is open in the direction of the surrounding ocean. This permits to search for a signature of particle showers induced by earth-skimming cosmic tau neutrinos in the PeV to EeV energy range arising from the ocean. We have studied the response of MAGIC to such events, employing Monte Carlo simulations of upward-going tau neutrino showers. The analysis of the show…
The MAGIC TeV gamma-ray telescopes have devoted several hundreds hour of observation time in about a decade, to hunt for particle dark matter indirect signatures in gamma rays, from various candidate targets of interest in the sky: the galactic center, satellite galaxies, galaxy clusters and unidentified objects in other bands. Despite the effort, no hints are present in MAGIC data. These observation are nevertheless not unusable. MAGIC indeed derived the most robust upper limits in the TeV range than any other instrument. These results, for the time being, only mildly constrain some classic d…
Terzan 5 is the only Galactic globular cluster that has plausibly been detected in the very-high-energy range. Stacking upper limits by H.E.S.S. on the integral $γ$-ray flux of a population of other globular clusters are very constraining for leptonic cluster emission models. We demonstrate that uncertainty in model parameters leads to a large spread in the predicted flux, and there are indeed regions in parameter space for which the stringent stacking upper limits are satisfied. We conduct two more case studies: we study the uncertainties in differential TeV flux for M15, showing that our mod…
MAGIC is a system of two Cherenkov telescopes located in the Canary island of La Palma. A key part of MAGIC Fundamental Physics program is the search for indirect signals of Dark Matter (DM) from different sources. In the Milky Way, DM forms an almost spherically symmetric halo, with a density peaked towards the center of the Galaxy and decreasing toward the outer region. We search for DM decay signals from the Galactic Halo, with a special methodology developed for this work. Our strategy is to compare pairs of observations performed at different angular distances from the Galactic Center, se…
We present the first search for signatures of brane-world extra-dimensional dark matter (DM) in the very-high-energy gamma-ray band by scrutinizing observations of the dwarf spheroidal galaxy Segue 1 with the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescope system. Branons are new degrees of freedom that appear within flexible brane-world models: they are weakly interacting massive particles and natural DM candidates. The ground-based gamma-ray telescopes MAGIC could indirectly detect branon DM in the multi-TeV mass range by observing secondary products of DM annihilation into Stand…
The extragalactic background light (EBL) is the radiation accumulated through the history of the Universe in the wavelength range from the ultraviolet to the far infrared. Local foregrounds make the direct measurement of the diffuse EBL notoriously difficult, while robust lower limits have been obtained by adding up the contributions of all the discrete sources resolved in deep infrared and optical galaxy observations. Gamma-ray astronomy has emerged in the past few years as a powerful tool for the study of the EBL: very-high-energy (VHE) photons traversing cosmological distances can interact …
Extreme high-energy peaked BL Lac objects (EHBLs) are a new emerging class of blazars. The typical two-hump structured spectral energy distribution (SED) is shifted to higher energies with respect to other more established classes of blazars. Multi-wavelength observations allow us to constrain their synchrotron peak in the medium and hard X-ray bands. Their gamma-ray emission dominates above the GeV gamma-ray band, and in some objects it extends up to several TeV (e.g. 1ES 0229+200). Their hard TeV spectrum is also interesting for the implications on the extragalactic background light indirect…
Radio continuum observations offer a new window on compact objects in globular clusters compared to typical X-ray or optical studies. As part of the MAVERIC survey, we have used the Australia Telescope Compact Array to carry out a deep (median central noise level of approximately 4 microJy per beam) radio continuum survey of 26 southern globular clusters at central frequencies of 5.5 and 9.0 GHz. This paper presents a catalogue of 1285 radio continuum sources in the fields of these 26 clusters. Considering the surface density of background sources, we find significant evidence for a population…
耀变体是一类活动星系核，其特征是相对论性喷流（喷流）朝向视线方向，是公认的河外TeV $γ$射线发射源。自2006年以来，MAGIC望远镜定期观测到三颗TeV亮耀变体Markarian（Mrk）421、Mrk 501和1 ES 1959+650，单次曝光时间为30至60分钟。MAGIC的灵敏度允许为每个这样的观测建立一个蟹状星云通量的30%的通量水平。在Mrk 421的情况下，在不同的时间尺度和X射线/TeV的排放量之间的高度相关性强通量的变化已被观察到。此外，还显示了2007/8年Mrk 501和1 ES 1959 +650光变曲线的初步测量结果。
Observation of the BL Lac objects 1ES 1215+303 and 1ES 1218+304 with the MAGIC telescopes
两个BL Lac天体1 ES 1215+303和1 ES 1218+304，相隔0.8度，在2010年和2011年被MAGIC望远镜观测到。2011年1月记录的20小时数据导致了1 ES 1215+303（也称为ON-325）在甚高能（>100 GeV）的首次探测。这一观测结果是由Tuorla blazar监测计划报告的光源的高光学状态触发的。与2010年1月至5月的25小时数据比较表明，1 ES 1215+303在2011年也在VHE伽马射线中闪耀。此外，Swift ToO的X射线观测表明，通量几乎是以前观测（2009年12月）的两倍。相反，1 ES 1218+304是一个众所周知的VHE伽马射线发射体，位于同一视场中，然后用MAGIC望远镜同时观察。近45小时的总观测时间允许测量这个源的光谱，其精度比MAGIC以前报告的要高得多。在这里，我们提出的MAGIC和多波长观测这两个VHE伽玛射线发射活动星系核的结果。
