A LEKSI C´1,M.DORO 2,S.LOMBARDI 3,D.NIETO 4 ON BEHALF OF THE MAGIC C OLLABORATION AND M. F ORNASA 5 1 Institut de F ´ sica d Altes Energ ´ es, Ed. While these limits are still not quite Gamma-ray line signatures can be expected in the very-high-energy (E_{Î³}>100 GeV) domain due to self-annihilation or decay of dark matter (DM) particles in space. Fornax which, contrary to the present HESS constraints of (ii), may allow for an interesting improvement and may become better than those from the current or MAGIC-I has been operational since 2004, and in, mode, they allow for observations of signiï¬cantly impro, Observations of Segue 1 were performed by MA, between January 2011 and February 2013, under the dark, night conditions, for zenith angle range between 13. , thus ensuring the low energy threshold of the analysis. matter, future prospects to do so are very good. We find that for a typical energy threshold of 100 GeV the flux, Join ResearchGate to discover and stay up-to-date with the latest research from leading experts in, Access scientific knowledge from anywhere. By using the full likelihood analysis, we take complete advantage of the distinct features expected in the gamma ray spectrum of Dark Matter origin, achieving better sensitivity with respect to the standard analysis chains. two-photon final state is 3.9(+7.1)(-3.7) x 10^-26 cm^3/s at 130 GeV, where the mode between January 2011 and February 2013, have, resulted in 157.9 hours of good quality data, thus making, this campaign the deepest survey of any dSph by any IA, The gathered data have been analyzed by means of the, full likelihood method. No statistically significant signal could be found. We critically re-examine recent claims that Segue 1 is a tidally disrupting star cluster and that kinematic samples are contaminated by the Sagittarius stream. In addition, its total baryonic content is, negligible and almost no background of conventional origin. On the other hand, the astrophysical factor is, determined by the dark matter density proï¬le of a speciï¬c, The typical annihilation (decay) gamma-ray spectrum, is predicted to be continuous and featureless, with photons, mainly produced from the pion decay and the ï¬nal state ra-, diation of charged particles. The kinematic signature of 300S was first discovered in spectroscopic studies of the Segue 1 dwarf galaxy as a separate stellar population moving at 300 km/s. Assuming a fermionic dark matter particle, that cou-, can be lifted by emission of a VIB photon. variety of decay modes, excluding half-lives up to ~10^26 to few 10^27 seconds. upper and lower, limits were calculated instead, for different models of dark, The considered scenarios include: annihilation and decay, into the ï¬nal state SM particles, direct annihilation and, decay into photon(s) and 3-body annihilation with virtual, internal bremsstrahlung (VIB) contribution. This is followed by, the details of the observations with MAGIC and subsequent, analysis. Segue 1, considered by many as possibly the most DM dominated satellite galaxy known in our galaxy. Those. Sebagai panduan kepada skala fizikal relatif Bima Sakti, jika telah dikurangkan kepada 130 km (80 batu) diameter, Sistem Suria pasti cuma 2 mm (0.08 inci) lebar. S11, on the other … Note that with a 1 km s −1 velocity dispersion, Segue 1 would have (M 1/2 /L 1/2) 150 within the half-light radius (if interpreted as a system in equilibrium) and therefore would still be among the most dark-matter-dominated satellites of the Milky Way (Walker et al. the Fermi Gamma-ray Space Telescope, The CTA (Cherenkov Telescope Array) Project. A totally new angle from DELTAt, the Tenmon Quartz wrist watch is a more simple, understated timepiece. experiment is an array of four identical imaging atmospheric It is located in the Pegasus constellation at the distance of about 17 kpc from the Sun and moves away from it with the velocity of 167.1 ± 1.5 km/s.. New interesting targets are recently found that are extremely dark matter dominated. strong enough to probe annihilation rates expected for thermally produced dark Kumpulan Tempatan yang terletak berhampiran sempadan ditarik ke dalam gugusan Virgo [1] . (2008) in which the authors computed the gamma-ray flux from DM annihilation associated to the halos of two reference dwarf Spheroidal galaxies, Draco and Willman 1. that such signals are most likely subdominant, the search for pronounced However, at least for the case of Willman 1 observed by CTA, boost factors may be below 10, even without considering the effect of substructures or the Sommerfeld enhancement. 2010). spectral features plays a key role for indirect detection experiments; Messier 54 (juga dikenali sebagai M54 atau NGC 6715 adalah kelompok globul dalam buruj Sagittarius.Ia telah ditemui oleh Charles Messier pada tahun 1778 dan kemudiannya dimasukkan dalam katalog objek seperti komet.M54 mudah dijumpai di langit, dekat dengan bintang ζ Sagittarii.Walau bagaimanapun, ia tidak dapat dileraikan menjadi bintang individu walaupun dengan teleskop amatur yang lebih besar. It describes the shape of the expected, spectrum and gives the number of photons produced above, a given energy threshold for the dark matter scenario in, question. Such a signal would be readily distinguishable from astrophysical Î³-ray sources that in most cases produce continuous spectra that span over several orders of magnitude in energy. <> The limits on the dark matter With almost 160 hours of good quality data, this is the deepest observational campaign on any dwarf galaxy carried so far by any Imaging Air Cherenkov Telescope. We present the results of the stereoscopic observations of Segue 1 with the MAGIC Telescopes, carried out between 2011 and 2013. within the dwarf galaxies. c et al., Journal of Cosmology and Astroparticle. launched by H.E.S.S.. of (i) the isotropic residual (extragalactic) background by Fermi and (ii) the SEGUE-2. It is located at a distance of about 23 kpc (about 75,000 light years) from the Sun and moves away from the Sun with the velocity of about 206 km/s. dedicated search for the latter in the data taken by the Fermi gamma-ray space Given that no signiï¬cant gamma-ray, signal was found, the limits are derived for annihilation and, decay rates assuming various dark matter models. 241302 doi:10.1103/PhysRevLett.107.241302. The observations are reviewed. This result confirms the previous measurements by the HESS experiment and indicates a steady source of TeV gamma-rays. West in 2005.. Properties. 5 0 obj No dark matter signal is detected. Among the targets suitable for dark matter searches, dwarf spheroidal galaxies are considered to be excellent candidates and, among them, Segue 1 stands out with mass-to-light ratio estimated to be of the order of 1000. of both instruments were replaced by the more advanced, DRS4-based conï¬gurations; by the end of 2012, among, other improvements, the camera of MAGIC-I w, to the exact replica of that of MAGIC-II [, performance of the system varied during the total period, of Segue 1 observations; therefore, data from each of the, different telescope states are analyzed separately, After the selection and data reduction procedures of, the MAGIC standard analysis chain, the total effecti, observation time amounted to 157.9 hours of good-quality, data. The original Sloan Extension for Galactic Understanding and Exploration (SEGUE-1) obtained spectra of nearly 240,000 stars of a range of spectral types. For monochromatic Î³-ray line emission, flux limits of (2Ã10^{-7}-2Ã10^{-5}) m^{-2} s^{-1} sr^{-1} and (1Ã10^{-8}-2Ã10^{-6}) m^{-2} s^{-1} sr^{-1} are obtained for the central part of the Milky Way halo and extragalactic observations, respectively. ResearchGate has not been able to resolve any citations for this publication. %�쏢 T, study as model-independent as possible, for all of the, channels the branching ratio is assumed to be 100%. Given spectral information of individual photon events from a sample of seven dwarf The resulting upper limits on the gamma-ray emission above 100 GeV are in the range of 4.6-7.5 x 10(-12) cm(-2) s(-1) for spectral indices from -1.5 to -2.5, thereby constraining the emission produced by cosmic rays, dark matter annihilations, and the central radio galaxy NGC 1275. option. The mass within the half-light radius is 5.8+8.2 â 3.1 Ã 105 M â. Segue 2 has a luminosity just 900 times that of our sun, the researchers report. Figure 9-1 lists the adaptive segues and how they behave in your app. The subsequent upper limit on the annihilation cross section to a MAGIC is a ground-based system of two, 17 m diameter, IACTs, located at the Roque de los Muchachos Observatory, a.s.l.). In particular, they rule out the interpretation in terms of decaying DM of the It consists of two clusters of galaxies in a "dumbbell" shape: the Milky Way and its satellites form one lobe, and the Andromeda Galaxy and its satellites constitute the other. The Sagittarius Dwarf Spheroidal Galaxy (Sgr dSph), also known as the Sagittarius Dwarf Elliptical Galaxy (Sgr dE or Sag DEG), is an elliptical loop-shaped satellite galaxy of the Milky Way.It contains four globular clusters, with the brightest of them – NGC 6715 (M54) – being known well before the discovery of the galaxy itself in 1994. On the other hand, if constraints from this work, are compared with those derived from Fermi-LA, the case of dark matter decay, the case of production of a, photon and a neutrino is considered: the lower limit on, spectrum and their impact on detection prospects is consid-, ered. Discovering the nature of dark matter is one of the most exciting tasks of modern science. We perform a joint analysis of dwarf galaxy data from the Fermi Gamma-ray Building on this success, SEGUE-2 spectroscopically observed around 120,000 stars, focusing on the in situ stellar halo of the Milky Way, from distances of 10 to 60 kpc. We derive new bounds on decaying Dark Matter from the gamma ray measurements Segue 1 has a noticeably elongated (ratio of axes ~ 2:1) shape with the half-light radiusof about 30 pc. For the first time, using gamma rays, we are able to rule out models with the most generic cross section (â¼3Ã10(-26)ââcm3 âs(-1) for a purely s-wave cross section), without assuming additional boost factors. errors reflect the systematic uncertainty in the distribution of dark matter Cn. p (17(h)45(m)20(s), -29 degrees 2'). weak indication, with a significance of 3.1\sigma (4.3\sigma) when (not) taking We find that those from (i) are among the most Plate numbers 3510 or larger are BOSS plates, taken with the new BOSS spectrograph. Segue 2 — карликова сфероїдальна галактика, розташована в сузір'ї Овна і виявлена 2009 року в даних, отриманих Слоанівським цифровим оглядом неба.. Характеристики. Instituto Nazionale di Astroï¬sica, I-00136 Rome, Italy. bremsstrahlung, in particular, provide smoking gun signatures. The Tenmon is a more playful companion, perfect for casual days and weekend getaways. into account the look-elsewhere effect, for an internal bremsstrahlung-like future extragalactic Fermi data. This is the longest exposure of any dSph galaxy by, The Segue 1 observations were analysed using the full, likelihood approach, an optimized analysis method that, takes complete advantage of the distinct features expected, in the gamma-ray spectrum of dark matter origin, achieving, better sensitivity with respect to the standard analysis of, ]. considered here, collider searches. The correspond-, orders of magnitude less constraining than the results from, H.E.S.S. The 95% confidence level upper limits range from about 10(-26)ââcm3 âs(-1) at 5 GeV to about 5Ã10(-23) ââcm3 âs(-1) at 1 TeV, depending on the dark matter annihilation final state. For the first time in such a study, we fully take into account the effect of internal bremsstrahlung, which has recently been shown to considerably enhance, in some cases, the gamma-ray flux at the high energies where Atmospheric Cherenkov Telescopes operate, thus leading to significantly harder annihilation spectra than traditionally considered. Silk, Physics Report 405 (2005). Located at a distance of, 23 kpc, this dSph is in the Northern hemisphere, outside of, the Galactic plane and visible to MAGIC for, dark time per year at low zenith angles. Search for Photon-Linelike Signatures from Dark Matter Annihilations with H.E.S.S. We search for dark matter particles with mass in the 100 GeV -10 TeV range, considering theoretical scenarios with different final state Standard Model particles, annihilation with internal bremsstrahlung and monochromatic line signals. Â© 2008-2020 ResearchGate GmbH. Nevertheless, some distincti, spectral features could be present, like monochromatic line. As an example, we review the gamma-ray dark matter detection prospects from Draco dwarf spheroidal galaxy at the MAGIC stereoscopic system and the CTA project. Satellite galaxies of the Milky Way are among the most promising targets for dark matter searches in gamma rays. (2009) revealed a group of stars moving near 300 km s−1 (with dispersion ... simultaneous spectra of 400 targets over a ﬁeld 2 in diameter. Including the uncertainty in the dark matter distribution, robust upper limits are placed on dark matter annihilation cross sections. Results are compatible with cosmological cluster simulations for the cosmic-ray-induced gamma-ray emission, constraining the average cosmic ray-to-thermal pressure to < 4% for the cluster core region (< 8% for the entire cluster). standard and contracted dark matter profiles. x��]Is\�q��o��8��P����j����,�H�H"G� �$@� g���YkV�|� I�|p����W[._.�U�����ns�����M�����WO�!6r�<9 �l��VɍTz�������z��B�a�΋wr������������o��l����A�ݓ�=��Ƀ? Furthermore, given its distance of only ˘23 kpc and position in the Northern hemi-sphere outside of the Galactic plane, Segue 1 has been dubbed an excellent candidate source for DM searches with MAGIC. telescope during its first 43 months. MAGIC is a ground-based system of two, 17 m diameter. 041301 doi:10.1103/PhysRevLett.110.041301. Among the dSphs, the ultra-faint galaxy Segue 1 stands out with M=L estimated to 3400 M =L [9]. We present a search for dark matter consisting of weakly interacting massive particles, applying a joint likelihood analysis to 10 satellite galaxies with 24 months of data of the Fermi Large Area Telescope. The Milky Way, meanwhile, is 20 billion times brighter. Based on photometric, kinematic, and metallicity information, we identify 71 stars as probable Segue 1 members, including some as far out as 87 pc. Fornax galaxy cluster by HESS. SEGUE-2 checked object or a SEGUE-1/southern survey target BossTarget The boss_target1 field is a bit mask specifying which BOSS target categories the object was selected in. For a DM particle mass of 1 TeV, limits on the velocity-averaged DM annihilation cross section â¨Ïvâ©_{ÏÏâÎ³Î³} reach â¼10^{-27} cm^{3} s^{-1}, based on the Einasto parametrization of the Galactic DM halo density profile. would be a fascinating possibility, we caution that a much more dedicated procedure to select optimal target regions that takes into account both We propose a dedicated analysis approach for indirect Dark Matter searches with Imaging Air Cherenkov Telescopes. In this work, I use APOGEE-2 and SEGUE survey data to map out the 300S stream. The Local Group is the galaxy group that includes the Milky Way.It has a total diameter of roughly 3 megaparsecs (9.8 Mly), and a total mass of the order of 2 × 10 12 solar masses (4.0 × 10 42 kg). reproduce the theoretical expectations very well. Segue is an open source collaborative content management system designed for e-learning that combines the ease of use of course management systems with the flexibility of weblogs for creating various types of sites including course, news, and journal. WIMPs are expected to annihilate or. Segue 1 has the highest estimated dark matter density of any known galaxy and will therefore be a prime testing ground for dark matter physics and galaxy formation on small scales. We present the results of a comprehensive Keck/DEIMOS spectroscopic survey of the ultra-faint Milky Way satellite galaxy Segue 1. @GG�S�Vy2�Tl�����r���n�v{�'7{��;=yag���ߦ�$��>L^���'g������I�����d�Ѳ��êɘ�K�/v{1��f�P����!������~�>�^���w�s�z�hg`qJ� We perform a The previously neglected, The next generation of ground-based Imaging Air Cherenkov Telescopes (IACTs) will play an important role in indirect dark matter searches. Download Segue CMS for free. -- Note that this is much faster than the standard "ORDER BY RANDOM()" SQL method. signal is also well fitted by a gamma-ray line at around 130 GeV. -- and 65000 to generate a random sample between 1 and 100% of the data -- respectively. experiment so far has been able to detect dark matter, directly of indirectly. This, added to the comparison with the prospects of detection by the Fermi satellite, clearly demonstrate that the answer to the question in the title is an affirmative one. In this Letter we present MAGIC observations of the Galactic center, resulting in the detection of a differential gamma-ray flux consistent with a steady, hard-slope power law, described as dN gamma/(dA dt dE) = (2.9 +/- 0.6) x 10(-12) (E/TeV)-2.2 +/- 0.2 cm(-2) s(-1) TeV-1. targets suitable for dark matter searches, dwarf spheroidal galaxies are considered to be excellent candidates and, among them, Segue 1 stands out with mass-to-light ratio estimated to be of the order of 1000. Cn. The boost factor is the quantity used to describe how far the experiment is from probing interesting DM scenarios and it is computed for the next generation of IACTs, namely MAGIC-II and CTA. Dark matter in satellite galaxies: Will future Imaging Air Cherenkov Telescopes play a role? Model particles, annihilation with internal bremsstrahlung and monochromatic line signals. Optimized analysis method for indirect dark matter searches with Imaging Air Cherenkov Telescopes, Fermi LAT search for dark matter in gamma-ray lines and the inclusive photon spectrum, MAGIC Gamma-ray Telescope Observation of the Perseus Cluster of Galaxies: Implications for Cosmic Rays, Dark Matter, and NGC 1275, A Complete Spectroscopic Survey of the Milky Way Satellite Segue 1: The Darkest Galaxy, Gamma ray constraints on Decaying Dark Matter, Constraining Dark Matter Models from a Combined Analysis of MilkyWay Satellites with the Fermi Large Area Telescope, Fermi LAT Search for Internal Bremsstrahlung Signatures from Dark Matter Halo Galaksi menjangkau luar tetapi terhad dalam saiz oleh orbit dua satelit Bima Sakti, Awan Magellan Besar dan Kecil di perigalaktikon pada ~180,000 tahun cahaya. For example, the behavior of a Show segue changes based on the presenting view controller. De-, as the squared ratio of the masses of the scalar and dark, VIB contribution is the most pronounced. Campus UAB, E-08193 Bellaterra, Spain 2 Universitat Aut onoma de Barcelona, E-08193 … We also show that contamination by the Sagittarius stream has been overestimated. Recently, the Galactic center has been reported to be a source of very high energy (VHE) gamma-rays by the CANGAROO, VERITAS, and HESS experiments. Regarding the decay into the ï¬nal state channel-, s, the dark matter particle lifetime is found to be of order, er limits estimated from the Fornax galaxy observations, with H.E.S.S., but from one to two orders of magnitude less, constraining (depending on the channel) than the bounds, Search for monochromatic line is done assuming direct, annihilation into two photons, and one photon and, Although these processes are highly loop suppressed, poten-, tial detection of line-like feature would provide a ï¬rm proof, of the dark matter existence, and also reveal some infor-, mation regarding the nature of its particle. and 1 TeV. Ƶ~2Bn�)��m��/��\��[��Ӭ�)3�d����Nf5�_M�1|�S0No�����0�j�� aѦ��{L��NYhl��/�eV�#���VX9��m�>�~����j�T��C��60_��ա��y nihilating or decaying WIMP, gamma-ray emission is expected. The obtained up-, acy of the considered model is more relevant, and limits, order of magnitude more constraining than the ones for the, case of less signiï¬cant VIB contribution (, considered channels, estimated bounds are up to two - three, orders of magnitude stronger than for the annihilation into. galaxies. The, dark matter particle mass takes values from the 100 GeV -, Furthermore, no additional boosts to the signal, either from, presence of substructures or from quantum effects were, In particular, constraints are calculated for the follow-, its for leptonic channels are even more stringent than the, constraints from this work are at least an order of magni-, tude stronger than the previous most sensitive MA, ]. Lastly, results are interpreted in the light of v. dark matter annihilation and decay scenarios. It was discovered by Beth Willman, Julianne J. Dalcanton, David Martinez-Delgado, and Andrew A. The preference, howe, given to the astrophysical sources of con, whose spectral distributions are nicely described, in majori-, analysis tools and methods of IACTs are adapted for such, signals, at the expense of sources whose emissions are pre-, dicted to contain some distinctive spectral features. Discovery. They were targeting stars in the red giant branch (RGB) locus. M. Ackermann et al., Physical Review D 86 (2012) 022002, A.Geringer-Sameth and S.M. used as standard in analysis chains of the IACTs. SDSS Legacy and SEGUE-1 cover plate numbers from 266 to 2974. Twenty paper disks (9 mm diameter) were immersed in the experimental solutions [0.1% CPC, 0.2% CPC, 2.5% NaOCl, 2.0% CHX (F.G.M., Joinville, SC, Brazil), and sterile distilled water] for 1 min and then 4 paper disks were placed over the BHIA surface in each agar plate. Using data collected with the H.E.S.S. contribution of Virtual Internal Bremsstrahlung is also taken into account, which produces, when present, a bump in the higher part of the energy spectrum. signals, constraints on the Dark Matter particle annihilation cross-section The notion of dark matter has been present for almost a, Observational evidence on all scales and cosmological, predictions indicate that dark matter represents almost 85%, of the matter content of our Universe, an almost 25% of its. We compute the improved limits that can be reached using this new approach, taking as an example existing estimates for several benchmark models as well as the recent results from VERITAS on observations of the dwarf spheroidal galaxy Segue 1. In the absence of clear choices are adopted. from direct dark matter annihilation (decay) into photon(s), or pronounced peak towards the kinematic limit from emis-, sion of virtual internal bremsstrahlung (VIB) photons [, The IACTs are observatories that deal with great v, of scientiï¬c objectives. limits are the strongest bounds, for the considered channels, from dSph observations by IACTs, and, for some models, and dark matter particle masses, even more constraining, The acquired results represent an improvement, with, respect to the previously most sensitive MA, searches, of an order of magnitude. We massive particles (WIMPs), that are of non-baryonic nature, produced thermally in the early Universe, and are stable on, cosmological scales. the most important tasks of modern science. signal that would correspond to a dark matter mass of \sim150 GeV; the same Nonadaptive segues are provided for apps that must also run on iOS 7, which does not support adaptive segues. Scientists have found the darkest known galaxy, a treasure trove of around 1,000 ancient, small and dim stars located just outside the Milky Way. The resulting, sample is to be used as a test area of the ever-e, The source chosen as the most suitable candidate is the, ultra-faint dSph galaxy Segue 1. The MAGIC Cherenkov telescopes perform searches at various putative dark matter targets for a decade now. When system went stereo, it, was opted to invest in a long-term observ, of the best dark matter candidate available to MA, accumulate many hours of good quality data. Dark matter signals from Draco and Willman 1: prospects for MAGIC II and CTA, Dark Matter searches with H.E.S.S. So replacing the "1" by a different number between 1 and 99 -- will generate a sample of the required percentage of objects. of high energy photons is enhanced by an order of magnitude in the stau coannihilation region, where the signal remains still at least three orders of magnitude below the sensitivity of the instruments. The H.E.S.S. Physics 06 (2011) 035 doi:10.1088/1475-7516/2011/06/035. ], the dwarf spheroidal galaxies (dSphs) Draco, last one is a still ongoing project, the rest of the results were, tens of hours of observations. The original Sloan Extension for Galactic Understanding and Exploration (SEGUE-1) obtained spectra of nearly 240,000 stars of a range of spectral types. These high energy gamma-rays can be used to All rights reserved. observation campaigns on dwarf satellite galaxies of the Milky Way were However, the effect of internal bremsstrahlung is negligible or small in more optimistic scenarios for detection like the funnel and focus point regions. For an, Addressing the question about the importance of future Imaging Air Cherenkov Telescopes (IACTs) for indirect detection of Dark Matter (DM), I will review the results of a paper by Bringmann et al. c, J. Rico and M. Martinez, Journal of Cosmology, J. Albert et al., The Astrophysical Journal Letters 638 (2006), c et al., The Astrophysical Journal 710 (2010), c et al., To appear in the Proceedings of the 33, c et al., Astroparticle Physics 35 (2012) 435-448. monochromatic gamma-ray lines or similar features related to internal Some possible The Origin of the 300 km/s Stream Near Segue 1. The energy spectra as measured by these experiments show substantial differences. Annihilation, Observation of Gamma Rays from the Galactic Center with the MAGIC Telescope, Dark matter line search using a joint analysis of dwarf galaxies with annihilation cross-section that we derive are stronger than what can be is how to disentangle possible signals from astrophysical backgrounds. This campaign is, expected to continue in the following years, and to leave, an important landmark in the ï¬eld in the pre-Cherenkov, Ä±sica de Canarias for the excellent working conditions at the, Observatorio del Roque de los Muchachos in La Palma. More importantly, this galaxy has the mass-to-light ratio estimated to, , making it the most dark matter dominated object, ]. SELECT TOP 100 u, g, r, i, z FROM Galaxy We briefly describe the observational technique used and the procedure implemented for the data analysis, and we discuss the results in the perspective of different models proposed for the acceleration of the VHE gamma-rays. Koushiappas, Physical Re, D 86 (2012) 021302 doi:10.1103/PhysRevD.86.021302, T. Bringmann et al., Journal of Cosmology and Astroparticle, Physics 07 (2012) 054 doi:10.1088/1475-7516/2012/07/054. The current searches are mainly, focused on dark matter composed of weakly interacting. A commonly encountered obstacle in indirect searches for galactic dark matter 2009a; Wolf et al. W, with mass in the 100 GeV - 10 TeV range, considering theoretical scenarios with dif. We give cross-section upper limits and decay lifetime lower limits for dark matter models that produce gamma-ray lines or contribute to the diffuse spectrum, including models proposed as explanations of the PAMELA and Fermi cosmic-ray data. Segue 1 is a dwarf spheroidal galaxy or globular cluster situated in the Leo constellation and discovered in 2006 by Sloan Digital Sky Survey. W, results of the stereoscopic observations of Segue 1 with the MA, 2013. Nominal positions of Segue 1 and η Leo are marked with the square and the star, respectively. e^\pm spectral features in Pamela, Fermi and HESS, unless very conservative Flux upper limits are presented for gamma-ray spectral lines from 7 to 200 GeV and for the diffuse gamma-ray background from 4.8 GeV to 264 GeV obtained from two years of Fermi Large Area Telescope data integrated over most of the sky. In this article, we consider two particularly promising candidate sources for dark matter annihilation signals, the nearby dwarf galaxies Draco and Willman 1, and study the prospects of detecting such a signal for the soon-operating MAGIC II telescope system. Diameter Diameter gugusan besar ini adalah kira-kira 200 juta tahun cahaya ; ia mengandungi 100 kumpulan dan gugusan galaksi dan mengandungi gugusan Virgo pada pusatnya. Being a small dwarf galaxy, it measures only a few thousand light-years in diameter.
2020 segue 1 diameter