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PoS(MULTIF15)020 http://pos.sissa.it/ http://pos.sissa.it/ al. d hard X-ray detector. A number rces. These results are of high sci- clude (1) revealing distributions of ted from 2005 July 10 to 2015 Au- Mn/Cr and Ni/Fe line ratios, and (4) equilibrium plasmas, and cosmic-ray ray spectroscopy available with both orkshop, 5210, Japan various fields. Among them, I will focus y discoveries of radiative-recombination 1 Machikaneyama-cho, Toyonaka, Aerospace Exploration Agency e Commons License Attribution-NonCommercial 4.0 Internation † ∗ [email protected] [email protected] Speaker. A footnote may follow. Suzaku was the Japanese 5th X-ray astronomy satellite opera continua, (3) constraining progenitors of Type Ia SNRs from acceleration. gust 26. Its key features are high-sensitivity wide-band X- on results on supernova remnants.supernova The ejecta, topics (2) in establishing over-ionized this plasmas paper b in searching for X-ray counterparts from unidentifiedentific HESS importance sou in physics of supernova explosions, non- the X-ray imaging CCD cameras and theof interesting non-imaging scientific collimate discoveries have been achieved in ∗ † Copyright owned by the author(s) under the terms of the Creativ Copyright owned by the author(s) under the terms of the Creative Commons c

Satoru Katsuda Suzaku Highlights of Supernova Remnants XI Multifrequency Behaviour of High Energy25-30 Cosmic May Sources 2015 W Palermo, Italy Institute of Space and Astronautical Science (ISAS), Japan (JAXA), 3-1-1 Yoshinodai, Chuo, Sagamihara, Kanagawa 252- Osaka 560-0043, Japan E-mail: Hiroshi Tsunemi Department of Earth and Space Science, Osaka University, 1- E-mail: © Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0). PoS(MULTIF15)020 Satoru Katsuda sights into SN oolant venting ly 10 [23], and ernova remnants re usually so hot m, we here focus ions but also into istributions of SN ed with the X-Ray allow for spatially- explosions that an- tic SNe. Combined ing surrounded by a y the high-sensitivity respond to the energy hysical laboratories to scale finger structures s (XIS) [19] and non- ervations of SNRs are nts. This capability is y and nearby . o. their shock waves (both arate line emission from us GINGA, and ROSAT, s in the X-ray sky. Since istributions of SN ejecta, recoils [48]. In addition, [17], on 2005 August 8, meter. Despite its initial saiced Suzaku and XMM- laxy. SNRs can be seen in sfully delivered a number 2 Msec, Suzaku and XMM- is figure shows that the central ∼ 2 ), we conducted a large, ◦ 1.4 ∼ K) that they emit X-rays most efficiently. 7 Since SNRs are observed as extended objects, we can directly reveal d Suzaku revealed detailed ejecta structures for a number of SNRs. Among the Suzaku was the Japanese 5th X-ray astronomy satellite launched in 2005 Ju Supernova remnants (SNRs) are the aftermaths of energetic supernova − 6 which is a strong observationalwith the merit high that spectral cannot resolution be ofdifferent Suzaku’s attained XIS, elements, with which we enables extragalac can us toimportant reveal sep ejecta to distributions constrain for recent individualejecta, SN eleme including explosion models Ni-rich that jetsdue predict plus to a standing O-rich accretion-shock variety torus instabilities of [35],SNRs structures d and offer [20, ejecta-neutron unique sites 37], to large- studythe mixing interstellar of medium SN (ISM) ejecta notimportant at in only a understanding during very metal-enrichment SN processes late explos in phase. the Universe, to Therefore, X-ray obs 2. Revealing Ejecta Distributions terminated the operation officially onwide-band 2015 X-ray August spectroscopy 26. performed Itimaging by is collimated X-ray characterized hard imaging b X-ray CCD detectorSpectrometer camera (HXD) which [33]. is Suzaku a wassuccess non-dispersive, also such high-resolution equipp as X-ray achievements spectro ofa an thermal energy short resolution between the ofto helium 7 space, and eV leaving neon onboard that tanksof system resulted important inoperable. in results, the thanks Nonetheless, liquid to(SNRs) helium Suzaku the that c succes are XIS mainly and derived HXD. from the We XIS. will review results on sup nounces deaths of .Thanks to There their are proximity, roughly theyexplosion are 400 mechanisms of SNRs as high well in scientific as ourstudy interest, SN non-equilibrium own nucleosynthesis. providing plasmas. galax us They Moreover, with are there in also isblastwaves and astrop growing reverse evidence shocks) that accelerate mostmany of wavelengths cosmic ranging rays from in radio the(10 ga to TeV gamma-rays. The SNR plasmas a Newton observations to cover theresolved spectroscopy. entire The fields remnant of view with are shownNewton sufficient in image Fig. depths 1 is left. that shown The in mo ranges Fig. of 1 0.2–0.6 keV, center, 0.6–1.2 keV, and for 1.2–2.0 which keV, respectively.region red, Th is harder green, than and the outermost blue regions, cor ASCA which is observations consistent [9, with previo 3, 27]. This implies that relatively hot SN ejecta, be Suzaku Highlights of SNRs 1. Supernova Remnants & The Suzaku Satellite on the results of the Cygnusthe Loop — Loop one is of quite the nearest large and (a brightest SNR radius of PoS(MULTIF15)020 (1) (2) rmediate. 1 Ejecta 1 redominantly Satoru Katsuda (0.5–0.6 keV), outhern part of analysis phases. Energy (keV) Energy (keV) ich are biased to sed to be respon- ular regions. Two s Si is concentrated rior of the remnant 0.5 2 view constructed by 0.5 2 ents non-equilibrium give reasonably good , as shown in Fig. 2. atially-resolved spec- that this asymmetry is Swept−up Swept−up . Overlaid boxes and circles 4 2 0 1 4 2 0 1 −3 −4 −3 −4 10 −2 −4 jecta is never uniform, but 10 −2 −4 0.1

0.1

10 10

0.01

10 10

0.01

cm keV s Counts

cm keV s Counts χ

−2 −1 −1

χ −2 −1 −1 he energy ranges of 0.2–0.6 keV, 0.6– tively. Center: Combined XIS and EPIC s, marked as (1) and (2), indicate regions spectra from the regions (1) and (2) shown in a components, respectively. Lower panels show (2) 3 (1) regions indicated in Fig. 1 center are presented in Fig. 1 ′ 3 × ′

Left: X-ray image of the entire Loop taken by ROSAT HRI W 1 degree

All of the published results used incomplete data sets that were available at the To reveal detailed spatial structures of SN ejecta, we have performed sp N We here use allMg the XI data (1.26–1.4 keV), sets Si inWe XIII can Fig. find (1.7–2.0 keV) 1, clearly to distinct and ainto distribution generate patterns; continuum the band O (1.4–1.7 central keV) is ratio part, rim-brightened, mapsarising and wherea from of Mg the O is swept-up VII comparatively medium,It uniform. while should Si be This is also dominated confirms notedthe by that that south SN O we and ejecta, confirm is are and clear p Mg extending asymmetric is to distributions inte the of southern Si, blow-out wh region. We suggest troscopy by dividing each fieldexample XIS of spectra view taken into from small 3 (a few arcminutes) rectang right. The spectra can be fittedionization with either model, a in single-component which or the two-compon low-sible and for the high-temperature swept-up components medium are and suppo fits the SN for ejecta, respectively. all These of models [40, the 12, spectra, 18, 41, often 42]. requiringhighly As two-component asymmetric described in model the in for sense thesethe the that papers, remnant. the the inte ejecta distribution are of preferentially e distributed in the s the central panel. Blue and red represent swept-up and eject relatively cool swept-up shell, occupy a large volume inside the remnant — a are Suzaku’s XIS and XMM-Newton’s EPICimage fields of of view, the respec Cygnus1.2 keV, Loop. and 1.2–2.0 Red, keV, respectively. green,where we and The extract blue blue spectra in correspond and the to red right t panels. boxe Right: XISresiduals. (BI) spectroscopic studies with ASCA [25, 26]. Figure 1: Suzaku Highlights of SNRs PoS(MULTIF15)020 s of galaxies ck for which k. Then, the Satoru Katsuda . trong radiative- hock heating in e RRC features tron temperature, , since the reverse ed" states [38]. r-ionized" state, in like ions compared .2+5.7 [13, 43], and has been revealed in e able to explain the e, we expect the elec- environmental effects e hot electrons start to ceeds in SNRs, so that ce of a dense wall in the from the ionization states. gnized in many SNRs since XI K (1.26–1.4 keV), and Si XIII IS and EPIC data. White contours overlaid ata. 4 Linearly-scaled band-ratio maps of O VII K (0.5–0.6 keV), Mg On the other hand, an opposite non-equilibration states, the so-called "ove The SNR plasmas are usually in non-equilibrium ionization states, unlike cluster Suzaku provided new insights into this problem, based on the discovery of s O VIIXI Mg Si XIII where we usually see relaxedSNRs plasmas. is This much is shorter simply than becauseeach the the elemental equilibration species time is timescale. after expected the to In s tron attain a the temperature mass-proportional SNR temperatur to (collisionless) sho beelectron much temperature lower gradually than increases through theionize interactions ion the with temperature nuclei. ions. right Therefore, Th the behindwe ionization the should (rather observe shoc than electron recombination) temperatures pro higherIn than fact, what such are under-ionized expected non-equilibrium conditions1980’s have [47, been 39, reco 24]. K (1.7–2.0 keV) to a continuum (1.4–1.7represent keV) X-ray based on intensities merged based X on ROSAT all-sky survey d caused by intrinsic SN explosionswere rather important, we than would environmental see effects; oppositelyshock if biased should ejecta the proceed distribution more (to in the the north) north north but than a in blow-out the in south, the south. givenmany the SNRs Subsequently, presen this (both kind CC of SNRs ejecta and asymmetry SN Ia 1006 SNRs) [45], indicating including the Puppis commonality A of [11, asymmetric, 14], uni-polar G156 SN explosions 3. Establishing Over-Ionized Plasmas Figure 2: Suzaku Highlights of SNRs which a plasma has awas higher claimed in ionization IC state 443 and than W49B, what basedwith on is those anomalously expected in high K-shell from He-like lines ions an in [15, H- elec X-ray 16]. spectrum However, with later an XMM-Newton equilibrum studies emission wer model, questioning the "over-ioniz recombination continua (RRC) from IC 443 [49]. The line ratios as well as th PoS(MULTIF15)020 ity, .24 and ho’s SNR oup elements covering tens Satoru Katsuda neutron-excess hi et al. (2015) a Chandrasekhar- nd Ni ed thermal X-rays RRC features [29, ity and Mn/Cr and d a little bit neutron- the metallicity of an include HESS J1614- ionized plasmas were ntified, and are called arf make the extreme se unID sources. As a they can not be origins . After this discovery, s of SNe Ia progenitors. s were found not to be ) is an important clue to NO-cycle converts C and rs, i.e., origins of cosmic are hard to be reconciled not have counterparts in X- een found only from mixed- e density of the white dwarf al other sources identified with Ne originates from N, which is the 22 3 times the solar values, respectively [36, 30]. 5 ∼ 1 and ∼ which can be attained only if white dwarfs are heavier than 3 − g cm 8 10 × Ne would produce more Mn. Meanwhile, 22 Ne, Mn, and Ni. If we assume that the amount of C and O represents the metallic 22 . Thus, in this scenario, the classical single-genenrate channel, in which Ne, more ⊙ To date, X-ray follow-ups have been performed for roughly half of the The H.E.S.S. collaboration has performed a survey of the Galactic plane, dis Recently, an extremely high Ni/Fe and Mn/Fe line ratios (or mass ratios of 0.11–0 Suzaku opened a new window to detect faint line emission from minor iron-gr 22 result, many of them were identified518 as [22], pulsar wind HESS nebulae J1825-137 (PWNe). [46],XMM-Newton These and HESS Chandra. J1837-069 Since [2], PWNe do andof not cosmic sever likely rays. accelerate protons, of new sources inassociated TeV with gamma-rays known [1]. sources in"TeV other unID Interestingly, wavelengths sources" about [10]. or 50 "dark Theyrays source particle stay (synchrotron accelerators". unide radiation), If they are theyrays. most really Therefore, likely do deep to follow-up be observations proton are accelerato eargely awaited. mass white dwarf is involved, is preferred as a progenitor star. 5. Identifying Unidentified TeV Gamma-Ray Sources 0.018–0.033, respectively) were found insolely 3C by 397 controlling [50]. the Thepostulated metallicity high that of ratios electron-caputure the processes progenitorneutron inside star. excess. the Therefore, exploding For Yamaguc white theneeds dw electron-caputure to be process higher to than occur, 2 the cor 1.2 M then we should expect aNi/Fe positive ratios correlation in between the SN theand ejecta. progenitor Kepler’s SNR meteallic Based were on estimated this to be method, the progenitor metallicities of Tyc product of CNO-cycle during H-burning inO a main into sequence N star. (practically), Since the C amountelements like of C and O controls the amount of N as well as Suzaku Highlights of SNRs are self-consistently explained by aroughly ten recombining SNRs (or were over-ionized) found plasma 28, to 32, show 44, 51]. recombining It plasmas should evidencedmorphology be by noted SNRs, the that i.e., the SNRs over-ionized plasmas assoiciated[31]. have with b This radio shells point plus mightformed. centrally-peak be the key to understand when and how these over- 4. Probing Type Ia Progenitors by Line Emission from Cr, Mn, Fe, a such as Cr, Mn, and Ni,Badenes whose intensity et ratios al.(2008) are sensitive [4] toexploding the noticed white propertie that dwarf. the Briefly, Mn/Cr neutronunderstanding excess ratio the of physics. strongly Mn Since depends (with the on respect compositionrich to of a Cr white dwarf is C, O, an PoS(MULTIF15)020 , e 1.5 , ApJL, PASJ, 61, Satoru Katsuda mbient matter [7]. consider a possible including HESS J1616- and ASTRO-H [34]. an be interpreted as the e current observation gap re, further observations are , PASJ, 61, S155 tors. However, their photon ulsar Wind .2+5.7 tingly, Fermi detected strong GeV , ARA&A, 47, 523 se Lines in Supernova Remnants A New Population of Very High Energy 05 X-Ray Studies of HESS J1837-069 with The Nuclear Spectroscopic Telescope Array Asymmetric Ejecta Distribution of the Cygnus Loop X-ray Observation of Very High Energy Gamma-Ray 6 , AIP Conference Proceeding, 1248, 33 Discovery of X-ray-emitting O-Ne-Mg-rich Ejecta in Suzaku Observations of Thermal and Non-Thermal The End of Amnesia: A New Method for Measuring the X-Ray-emitting Ejecta in Puppis A Observed with Suzaku Discovery of a Possible X-Ray Counterpart to HESS , A&A, 341, 602 , ApJ, 714, 1725 , ApJ, 770, 103 ROSAT all-sky survey map of the Cygnus Loop: Overall , ApJ, 691, 1854 , Science, 307, 1938 Teraelectronvolt Astronomy Spatial structure of the Cygnus loop in the X-ray region abov , PASJ, 60, S107 High energy aspects of SNRs , PASJ, 59, S209 , PASJ, 362, 566 Suzaku and ASCA: a VHE Gamma-Ray Source Originated from the P S183 structure and comparison with radio map Metallicity of Type Ia Supernova Progenitors Using Mangane 680, L33 (NuSTAR) High-energy X-Ray Mission Revealed with Suzaku ApJ, 676, 378 Gamma-Ray Sources in the Milky Way the Galactic Puppis X-Ray Emission from the Middle-Aged Supernova Remnant G156 Source, HESS J1745-303, with Suzaku J1804-216 keV On the other hand, Suzaku gave strict upper limits for some other sources, [3] Aschenbach, B., & Leahy, D.A. 1999, [2] Anada, T., Ebisawa, K., Dotani, T., & Bamba, A. 2009, [7] Bamba, A. 2010, [5] Bamba, A., Koyama, K., Hiraga, J.S. 2007, [4] Badenes, C., Bravo, E., & Hughes, J.P. 2008, [9] Hatsukade, I., & Tsunemi, H. 1990, [8] Harrison, F.A., Craig, W.W., Christensen, F.E. 2013, [1] Aharonian, F., Akhperjanian, A.G., Aye, K.-M., et al. 20 [6] Bamba, A., Yamazaki, R., Kohri, K., et al. 2009, [12] Katsuda, S., Tsunemi, H., Miyata, E., et al. 2008, [14] Katsuda, S., Hwang, U., Petre, R., et al. 2010, [13] Katsuda, S., Petre, R., Hwang, U., et al. 2009, 508 [21], HESS J1745-303 [6], and HESSgamma-ray J1804-216 emission [5]. from Interes HESS J1616-508 andpion-decay HESS J1804-216, bump which due c to interactionsThese between sources are accelerated therefore nucleons promising withindices candidates the would of be a proton too accelera spectral steep softening to during produce cosmic-ray observed propagation cosmic-raydesired to to the spectrum, understand earth. if their Therefo nature(s). we between In 10 particular, keV it and is 1 essential GeV, part to of fill which th will be covered with NuSTARReferences [8] Suzaku Highlights of SNRs [10] Hinton, J.A., & Hofmann, W. 2009, [11] Hwang, U., Petre, R., Flanagan, K.A. 2008, PoS(MULTIF15)020 , . 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