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. 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. During this period, the telescopes underwent a series of, signiï¬cant changes: at the end of 2011, the readout systems. the same ï¬nal states, but without the VIB photons. W, results of the stereoscopic observations of Segue 1 with the MA, 2013. Predictions are made on improvement that can be achieved for MAGIC and CTA. 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). 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. Instituto Nazionale di Astroï¬sica, I-00136 Rome, Italy. experiment so far has been able to detect dark matter, directly of indirectly. 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. To this end, we use a new adaptive 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. The Origin of the 300 km/s Stream Near Segue 1. The Tenmon is a more playful companion, perfect for casual days and weekend getaways. The current searches are mainly, focused on dark matter composed of weakly interacting. The original Sloan Extension for Galactic Understanding and Exploration (SEGUE-1) obtained spectra of nearly 240,000 stars of a range of spectral types. procedure to select optimal target regions that takes into account both 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. 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. Î³-ray instrument, upper limits on linelike emission are obtained in the energy range between â¼500 GeV and â¼25 TeV for the central part of the Milky Way halo and for extragalactic observations, complementing recent limits obtained with the Fermi-LAT instrument at lower energies. More importantly, this galaxy has the mass-to-light ratio estimated to, , making it the most dark matter dominated object, ]. galaxies. 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. 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. analysis and additional data will be necessary to rule out or confirm this bremsstrahlung, in particular, provide smoking gun signatures. With the, mass range predicted for WIMPs, those photons might be, visible in the gamma-ray domain, currently best explored, The gamma-ray ï¬ux from dark matter annihilation or, decay that is to be measured on Earth is determined by two, independent factors: one, coming from the particle physics, and other, related to the astrophysics. have been derived in different particle physics scenarios. The extremely low metallicities ([Fe/H] < â3) of two Segue 1 stars and the large metallicity spread among the members demonstrate conclusively that Segue 1 is a dwarf galaxy, and we find no evidence in favor of tidal effects. SEGUE could be used for spatial phase unwrapping in other applications such as X-ray phase contrast imaging, synthetic aperture radar interferometry, and 3D shape measurement or profilometry. T, study as model-independent as possible, for all of the, channels the branching ratio is assumed to be 100%. c et al., Journal of Cosmology and Astroparticle. massive particles (WIMPs), that are of non-baryonic nature, produced thermally in the early Universe, and are stable on, cosmological scales. We derive new bounds on decaying Dark Matter from the gamma ray measurements nihilating or decaying WIMP, gamma-ray emission is expected. We perform a joint analysis of dwarf galaxy data from the Fermi Gamma-ray Pictoris 1 is approximately 370,000 light-years away and has a diameter of about 200 light-years. 041301 doi:10.1103/PhysRevLett.110.041301. considered here, collider searches. Figure 9-1 lists the adaptive segues and how they behave in your app. two-photon final state is 3.9(+7.1)(-3.7) x 10^-26 cm^3/s at 130 GeV, where the 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. With a total luminosity less than that of a single bright red giant and a V-band mass-to-light ratio of 3400 M â/L â, Segue 1 is the darkest galaxy currently known. the most important tasks of modern science. line searches in the central Galactic Halo [, one to two orders of magnitude weaker than the Fermi-LA, analyses. strong enough to probe annihilation rates expected for thermally produced dark The Perseus galaxy cluster was observed by the MAGIC Cherenkov telescope for a total effective time of 24.4 hr during 2008 November and December. This is the largest survey ever ... 17 m diameter IACTs, located at the Observatory Roque de los Mucha- 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 work, I use APOGEE-2 and SEGUE survey data to map out the 300S stream. Cn. We propose a dedicated analysis approach for indirect Dark Matter searches with Imaging Air Cherenkov Telescopes. 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, ]. In the absence of clear New interesting targets are recently found that are extremely dark matter dominated. 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. 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 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. ], the dwarf spheroidal galaxies (dSphs) Draco, last one is a still ongoing project, the rest of the results were, tens of hours of observations. So replacing the "1" by a different number between 1 and 99 -- will generate a sample of the required percentage of objects. 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. 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. Some possible launched by H.E.S.S.. Search for Photon-Linelike Signatures from Dark Matter Annihilations with H.E.S.S. 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. No signiﬁcant gamma-ray emission was found above the background in around30 hours of observation. Segue 3 is a faint star cluster of the Milky Way galaxy discovered in 2010 in the data obtained by Sloan Digital Sky Survey. 3.2 Likelihood analysis The, support of the German BMBF and MPG, the Italian INFN, the, Swiss National Fund SNF, and the Spanish MICINN is grateful-, ly acknowledged. stream However we note that because the signal aperture is matched to the angular size of the MAGIC PSF, this truncation has a negligible impact on the sensitivity of the analysis. 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.. It features a quartz movement housed in a stainless steel case and protected by a sapphire crystal. Space Telescope in search of dark matter annihilation into a gamma-ray line. Segue 2 has a luminosity just 900 times that of our sun, the researchers report. We also show that contamination by the Sagittarius stream has been overestimated. A commonly encountered obstacle in indirect searches for galactic dark matter observation campaigns on dwarf satellite galaxies of the Milky Way were 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. Segue 2 — карликова сфероїдальна галактика, розташована в сузір'ї Овна і виявлена 2009 року в даних, отриманих Слоанівським цифровим оглядом неба.. Характеристики. @GG�S�Vy2�Tl�����r���n�v{�'7{��;=yag���ߦ�\$��>L^���'g������I�����d�Ѳ��êɘ�K�/v{1��f�P����!������~�>�^���w�s�z�hgqJ� variety of decay modes, excluding half-lives up to ~10^26 to few 10^27 seconds. Kumpulan Tempatan yang terletak berhampiran sempadan ditarik ke dalam gugusan Virgo [1] . In addition, its total baryonic content is, negligible and almost no background of conventional origin. After correcting for the influence of binary stars using repeated velocity measurements, we determine a velocity dispersion of 3.7+1.4 â 1.1 km sâ1. 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. Dwarf galaxies show no evidence of a gamma-ray line between 10 GeV 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. The correspond-, orders of magnitude less constraining than the results from, H.E.S.S. 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 fact, we already find a 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. p (17(h)45(m)20(s), -29 degrees 2'). (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. 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. (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. All content in this area was uploaded by Jelena AleksiÄ on Jul 18, 2014, Ä±es, Ed. 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. signals, constraints on the Dark Matter particle annihilation cross-section method is tested by a subsampling analysis of the full sky data and found to dedicated search for the latter in the data taken by the Fermi gamma-ray space The subsequent upper limit on the annihilation cross section to a Segue 1 has a noticeably elongated (ratio of axes ~ 2:1) shape with the half-light radiusof about 30 pc. e^\pm spectral features in Pamela, Fermi and HESS, unless very conservative Being a small dwarf galaxy, it measures only a few thousand light-years in diameter. annihilation cross-section that we derive are stronger than what can be The analysis of the data is performed using a dedicated likelihood approach, optimized for signals with characteristic spectral features. 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). search for annihilations of Dark Matter particles in dense environments. Segue 1 significance skymap above 150 GeV, from 157.9 hours of observations. MAGIC can hunt this signature in the night sky. 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. While these limits are still not quite Nonadaptive segues are provided for apps that must also run on iOS 7, which does not support adaptive segues. signal is also well fitted by a gamma-ray line at around 130 GeV. 2009a; Wolf et al. 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. SEGUE-2 covers plate numbers 3000 to 3509; all spectra on these plates were measured with the SDSS-I/-II spectrograph. 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. Here are presented the details on the latest dark matter, presented, together with the motivation behind the choice of, Segue 1 as a suitable dark matter target. We also discuss future prospects for CTA bounds from Due to the presence of spectral features, the boost factors can vary, becoming dependent to the characteristics of the particular DM candidate, obstacling a clear statement about prospects of detection. Lastly, results are interpreted in the light of v. dark matter annihilation and decay scenarios. Using data collected with the H.E.S.S. Dark matter particle annihilation or decay can produce monochromatic gamma-ray lines and contribute to the diffuse gamma-ray background. We describe the method and characterize its general performance. 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, ]. Several 5 0 obj We also compare its sensitivity with that of the current standards for several Dark Matter annihilation models, obtaining gains of up to factors of order of 10. the Fermi Gamma-ray Space Telescope, The CTA (Cherenkov Telescope Array) Project. Plate numbers 3510 or larger are BOSS plates, taken with the new BOSS spectrograph. M. Ackermann et al., Physical Review D 86 (2012) 022002, A.Geringer-Sameth and S.M. 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. Cherenkov telescopes in the Southern hemisphere, designed to observe very high errors reflect the systematic uncertainty in the distribution of dark matter For example, the behavior of a Show segue changes based on the presenting view controller. We revise the impact of internal bremsstrahlung photons in the context of the constrained minimal supersymmetric standard model on gamma-ray dark matter annihilation searches. The stellar kinematics of Segue 1 require very high mass-to-light ratios unless the system is far from dynamical equilibrium, even if the period distribution of unresolved binary stars is skewed toward implausibly short periods. West in 2005.. Properties. 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. MAGIC is a ground-based system of two, 17 m diameter. 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. Each survey has a number of different programs. Campus UAB, E-08193 Bellaterra, Spain 2 Universitat Aut onoma de Barcelona, E-08193 … is expected from this source at very high energies. 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. Silk, Physics Report 405 (2005). In particular, they rule out the interpretation in terms of decaying DM of the W, with mass in the 100 GeV - 10 TeV range, considering theoretical scenarios with dif. The previously neglected, The next generation of ground-based Imaging Air Cherenkov Telescopes (IACTs) will play an important role in indirect dark matter searches. Fornax galaxy cluster by HESS. 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. The observable ﬂux in the MAGIC analysis of Segue 1 is therefore reduced by a factor of ˘1.6 with respect to the LAT analysis of the same target. It was discovered by Beth Willman, Julianne J. Dalcanton, David Martinez-Delgado, and Andrew A. The gamma-ray source is centered at (R.A., decl.) 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. galaxy dynamics shows that they are Dark Matter-dominated environments. SEGUE-2. De-, as the squared ratio of the masses of the scalar and dark, VIB contribution is the most pronounced. This work was also supported by the Marie, CSD2009-00064 projects of the Spanish Consolider Ingenio 2010, programme, by grant DO02-353 of the Bulgarian NSF, by grant, 127740 of the Academy of Finland, by the YIP of the Helmholtz, Gemeinschaft, by the DFG Cluster of Excellence Origin and Struc-, ture of the Universe, and by the Polish MNiSzW grant 745/N-, G. Bertone, D. Hooper and J. "��쳥��j��8uCѧm���4�� ��2�X���� ��ڹ�@Q��� �C�k�&6�5)��f��;Bn>��&k(�6B ��P@�\g��RO�& x�SЫu���@�����;#��-�z/��������/Q�¤g��ى�Y���r��o����l� �@ ����� �2۳��IG[�}]�(�߾����T�H��6��)�McGuF��O���ަ��8�ڃ8�s�ä�cs �����Ӵ���]�y[�E����"o@1�Si�����-����3���s�w��zn���I+C��m|4�. This result confirms the previous measurements by the HESS experiment and indicates a steady source of TeV gamma-rays. The limits on the dark matter 32 ND INTERNATIONAL C OSMIC R AY C ONFERENCE,BEIJING 2011 Segue 1: the best dark matter candidate dwarf galaxy surveyed by MAGIC J. used as standard in analysis chains of the IACTs. Segue 2 is a dwarf spheroidal galaxy situated in the constellation Aries and discovered in 2009 in the data obtained by Sloan Digital Sky Survey.The galaxy is located at the distance of about 35 kiloparsecs (35,000 parsecs; 110,000 light-years) from the Sun and moves towards the Sun at a speed of 40 km/s. signal that would correspond to a dark matter mass of \sim150 GeV; the same 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. 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. The behaviour of our statistical 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.
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