Luminosity Functions of Cluster Galaxies
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A Lack of Evidence for Global Ram-Pressure Induced Star Formation in the Merging Cluster Abell 3266
Draft version March 31, 2021 Typeset using LATEX default style in AASTeX62 A Lack of Evidence for Global Ram-pressure Induced Star Formation in the Merging Cluster Abell 3266 Mark J. Henriksen1 and Scott Dusek1 1University of Maryland, Baltimore County Physics Department 1000 Hilltop Circle Baltimore, MD USA ABSTRACT Interaction between the intracluster medium and the interstellar media of galaxies via ram-pressure stripping (RPS) has ample support from both observations and simulations of galaxies in clusters. Some, but not all of the observations and simulations show a phase of increased star formation compared to normal spirals. Examples of galaxies undergoing RPS induced star formation in clusters experiencing a merger have been identified in high resolution optical images supporting the existence of a star formation phase. We have selected Abell 3266 to search for ram-pressure induced star formation as a global property of a merging cluster. Abell 3266 (z = 0.0594) is a high mass cluster that features a high velocity dispersion, an infalling subcluster near to the line of sight, and a strong shock front. These phenomena should all contribute to making Abell 3266 an optimum cluster to see the global effects of RPS induced star formation. Using archival X-ray observations and published optical data, we cross-correlate optical spectral properties ([OII, Hβ]), indicative of starburst and post-starburst, respectively with ram-pressure, ρv2, calculated from the X-ray and optical data. We find that post- starburst galaxies, classified as E+A, occur at a higher frequency in this merging cluster than in the Coma cluster and at a comparable rate to intermediate redshift clusters. -
Curriculum Vitae Avishay Gal-Yam
January 27, 2017 Curriculum Vitae Avishay Gal-Yam Personal Name: Avishay Gal-Yam Current address: Department of Particle Physics and Astrophysics, Weizmann Institute of Science, 76100 Rehovot, Israel. Telephones: home: 972-8-9464749, work: 972-8-9342063, Fax: 972-8-9344477 e-mail: [email protected] Born: March 15, 1970, Israel Family status: Married + 3 Citizenship: Israeli Education 1997-2003: Ph.D., School of Physics and Astronomy, Tel-Aviv University, Israel. Advisor: Prof. Dan Maoz 1994-1996: B.Sc., Magna Cum Laude, in Physics and Mathematics, Tel-Aviv University, Israel. (1989-1993: Military service.) Positions 2013- : Head, Physics Core Facilities Unit, Weizmann Institute of Science, Israel. 2012- : Associate Professor, Weizmann Institute of Science, Israel. 2008- : Head, Kraar Observatory Program, Weizmann Institute of Science, Israel. 2007- : Visiting Associate, California Institute of Technology. 2007-2012: Senior Scientist, Weizmann Institute of Science, Israel. 2006-2007: Postdoctoral Scholar, California Institute of Technology. 2003-2006: Hubble Postdoctoral Fellow, California Institute of Technology. 1996-2003: Physics and Mathematics Research and Teaching Assistant, Tel Aviv University. Honors and Awards 2012: Kimmel Award for Innovative Investigation. 2010: Krill Prize for Excellence in Scientific Research. 2010: Isreali Physical Society (IPS) Prize for a Young Physicist (shared with E. Nakar). 2010: German Federal Ministry of Education and Research (BMBF) ARCHES Prize. 2010: Levinson Physics Prize. 2008: The Peter and Patricia Gruber Award. 2007: European Union IRG Fellow. 2006: “Citt`adi Cefal`u"Prize. 2003: Hubble Fellow. 2002: Tel Aviv U. School of Physics and Astronomy award for outstanding achievements. 2000: Colton Fellow. 2000: Tel Aviv U. School of Physics and Astronomy research and teaching excellence award. -
On the Nature of Filaments of the Large-Scale Structure of the Universe Irina Rozgacheva, I Kuvshinova
On the nature of filaments of the large-scale structure of the Universe Irina Rozgacheva, I Kuvshinova To cite this version: Irina Rozgacheva, I Kuvshinova. On the nature of filaments of the large-scale structure of the Universe. 2018. hal-01962100 HAL Id: hal-01962100 https://hal.archives-ouvertes.fr/hal-01962100 Preprint submitted on 20 Dec 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. On the nature of filaments of the large-scale structure of the Universe I. K. Rozgachevaa, I. B. Kuvshinovab All-Russian Institute for Scientific and Technical Information of Russian Academy of Sciences (VINITI RAS), Moscow, Russia e-mail: [email protected], [email protected] Abstract Observed properties of filaments which dominate in large-scale structure of the Universe are considered. A part from these properties isn’t described within the standard ΛCDM cosmological model. The “toy” model of forma- tion of primary filaments owing to the primary scalar and vector gravitational perturbations in the uniform and isotropic cosmological model which is filled with matter with negligible pressure, without use of a hypothesis of tidal interaction of dark matter halos is offered. -
Report of Contributions
Mapping the X-ray Sky with SRG: First Results from eROSITA and ART-XC Report of Contributions https://events.mpe.mpg.de/e/SRG2020 Mapping the X- … / Report of Contributions eROSITA discovery of a new AGN … Contribution ID : 4 Type : Oral Presentation eROSITA discovery of a new AGN state in 1H0707-495 Tuesday, 17 March 2020 17:45 (15) One of the most prominent AGNs, the ultrasoft Narrow-Line Seyfert 1 Galaxy 1H0707-495, has been observed with eROSITA as one of the first CAL/PV observations on October 13, 2019 for about 60.000 seconds. 1H 0707-495 is a highly variable AGN, with a complex, steep X-ray spectrum, which has been the subject of intense study with XMM-Newton in the past. 1H0707-495 entered an historical low hard flux state, first detected with eROSITA, never seen before in the 20 years of XMM-Newton observations. In addition ultra-soft emission with a variability factor of about 100 has been detected for the first time in the eROSITA light curves. We discuss fast spectral transitions between the cool and a hot phase of the accretion flow in the very strong GR regime as a physical model for 1H0707-495, and provide tests on previously discussed models. Presenter status Senior eROSITA consortium member Primary author(s) : Prof. BOLLER, Thomas (MPE); Prof. NANDRA, Kirpal (MPE Garching); Dr LIU, Teng (MPE Garching); MERLONI, Andrea; Dr DAUSER, Thomas (FAU Nürnberg); Dr RAU, Arne (MPE Garching); Dr BUCHNER, Johannes (MPE); Dr FREYBERG, Michael (MPE) Presenter(s) : Prof. BOLLER, Thomas (MPE) Session Classification : AGN physics, variability, clustering October 3, 2021 Page 1 Mapping the X- … / Report of Contributions X-ray emission from warm-hot int … Contribution ID : 9 Type : Poster X-ray emission from warm-hot intergalactic medium: the role of resonantly scattered cosmic X-ray background We revisit calculations of the X-ray emission from warm-hot intergalactic medium (WHIM) with particular focus on contribution from the resonantly scattered cosmic X-ray background (CXB). -
Interstellarum 45 1 Zeitschrift Für Praktische Astronomie
fokussiert Liebe Leserinnen, liebe Leser, die Sonnenfi nsternis am 29. März steht ganz im Fokus dieser Ausgabe. Während wir Daten, Karten und Beobachtungshinweise bereits im letzten Heft vorgestellt hatten (nachzubestellen über www.interstellarum.de), gehen wir in dieser Ausgabe auf einzelne As- pekte der Finsternisbeobachtung näher ein. Astro-Neulinge erhalten in unserer Einsteiger-Serie Grundwissen über die Sonne und ihre gefahrlose Beobachtung (Seite 28). Für Astro-Experten gibt Wolf- gang Strickling ausführliche Tipps zur Beobachtung der fl üchtigen Fliegenden Schatten, die kurz vor und nach der totalen Phase einer Sonnenfi nsternis auftreten (Seite 36). Über interessante Beobach- tungen am Rand der Finsterniszone vom 3. Oktober des vergangenen Jahres berichtet außerdem Dirk Ewers (Seite 32). Das Titelbild dieser Ausgabe gelang Stefan Binnewies am 26.2.1998 auf Aruba mit einem 93/840mm-Refraktor mit 1,4fach-Konverter; das Bild ist ein digitales Komposit aus einer 1/2s und einer 2s belichteten Aufnahme auf Fuji Velvia 50 ASA (Rollfi lm). Leider abgesagt werden musste die interstellarum-Leserreise zur Finsternis nach Ägypten. Der Bonner Firma Eclipse-Reisen.de gelang es nicht, die Reise wie vereinbart in ihr Online-Angebot aufzuneh- men. Dadurch war es Interessenten nicht möglich, sich wie geplant im Internet für die Leserreise anzumelden, sodass nach Auskunft des Anbieters die Mindestteilnehmerzahl nicht erreicht wurde – wäh- renddessen die Aufmerksamkeit auf eine nahezu identische Reise ohne Beteiligung durch interstellarum gelenkt wurde. Auch nach mehrfacher Bitte um Einhaltung der Vereinbarung änderte sich dar- an nichts. Stefan Binnewies Wie sicher sind Sonnenfi lter? Augenschäden werden nach Finsternis- Beobachtungen immer wieder gemeldet. Mit einer aufwändigen Messung ist Peter Höbel der Frage nachgegangen, ob die im Ama- teurbereich verbreiteten Objektivsonnenfi lter aus Glas und Folie die geltenden Sicherheitsnormen einhalten (Seite 63). -
Galaxy Clusters in the Swift/BAT Era: Hard X-Rays in The
Submitted to Astrophysical Journal Galaxy Clusters in the Swift/BAT era: Hard X-rays in the ICM M. Ajello1, P. Rebusco2, N. Cappelluti1,3, O. Reimer4, H. B¨ohringer1, J. Greiner1, N. Gehrels5, J. Tueller5 and A. Moretti6 [email protected] ABSTRACT We report about the detection of 10 clusters of galaxies in the ongoing Swift/BAT all-sky survey. This sample, which comprises mostly merging clusters, was serendipitously detected in the 15–55 keV band. We use the BAT sample to investigate the presence of excess hard X-rays above the thermal emission. The BAT clusters do not show significant (e.g. ≥2 σ) non-thermal hard X-ray emis- sion. The only exception is represented by Perseus whose high-energy emission is likely due to NGC 1275. Using XMM-Newton, Swift/XRT, Chandra and BAT data, we are able to produce upper limits on the Inverse Compton (IC) emission mechanism which are in disagreement with most of the previously claimed hard X-ray excesses. The coupling of the X-ray upper limits on the IC mechanism to radio data shows that in some clusters the magnetic field might be larger than 0.5 µG. We also derive the first log N - log S and luminosity function distribution of galaxy clusters above 15 keV. Subject headings: galaxies: clusters: general – acceleration of particles – radiation arXiv:0809.0006v1 [astro-ph] 30 Aug 2008 mechanisms: non-thermal – magnetic fields – X-rays: general 1Max Planck Institut f¨ur Extraterrestrische Physik, P.O. Box 1603, 85740, Garching, Germany 2Kavli Institute for Astrophysics and Space Research, MIT, Cambridge, MA 02139, USA 3University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 4W.W. -
A Review on Substellar Objects Below the Deuterium Burning Mass Limit: Planets, Brown Dwarfs Or What?
geosciences Review A Review on Substellar Objects below the Deuterium Burning Mass Limit: Planets, Brown Dwarfs or What? José A. Caballero Centro de Astrobiología (CSIC-INTA), ESAC, Camino Bajo del Castillo s/n, E-28692 Villanueva de la Cañada, Madrid, Spain; [email protected] Received: 23 August 2018; Accepted: 10 September 2018; Published: 28 September 2018 Abstract: “Free-floating, non-deuterium-burning, substellar objects” are isolated bodies of a few Jupiter masses found in very young open clusters and associations, nearby young moving groups, and in the immediate vicinity of the Sun. They are neither brown dwarfs nor planets. In this paper, their nomenclature, history of discovery, sites of detection, formation mechanisms, and future directions of research are reviewed. Most free-floating, non-deuterium-burning, substellar objects share the same formation mechanism as low-mass stars and brown dwarfs, but there are still a few caveats, such as the value of the opacity mass limit, the minimum mass at which an isolated body can form via turbulent fragmentation from a cloud. The least massive free-floating substellar objects found to date have masses of about 0.004 Msol, but current and future surveys should aim at breaking this record. For that, we may need LSST, Euclid and WFIRST. Keywords: planetary systems; stars: brown dwarfs; stars: low mass; galaxy: solar neighborhood; galaxy: open clusters and associations 1. Introduction I can’t answer why (I’m not a gangstar) But I can tell you how (I’m not a flam star) We were born upside-down (I’m a star’s star) Born the wrong way ’round (I’m not a white star) I’m a blackstar, I’m not a gangstar I’m a blackstar, I’m a blackstar I’m not a pornstar, I’m not a wandering star I’m a blackstar, I’m a blackstar Blackstar, F (2016), David Bowie The tenth star of George van Biesbroeck’s catalogue of high, common, proper motion companions, vB 10, was from the end of the Second World War to the early 1980s, and had an entry on the least massive star known [1–3]. -
A Lack of Evidence for Global Ram-Pressure Induced Star Formation in the Merging Cluster Abell 3266
International Journal of Astronomy and Astrophysics, 2021, 11, 95-132 https://www.scirp.org/journal/ijaa ISSN Online: 2161-4725 ISSN Print: 2161-4717 A Lack of Evidence for Global Ram-Pressure Induced Star Formation in the Merging Cluster Abell 3266 Mark J. Henriksen, Scott Dusek Physics Department, University of Maryland, Baltimore, MD, USA How to cite this paper: Henriksen, M.J. and Abstract Dusek, S. (2021) A Lack of Evidence for Global Ram-Pressure Induced Star Forma- Interaction between the intracluster medium and the interstellar media of ga- tion in the Merging Cluster Abell 3266. In- laxies via ram-pressure stripping (RPS) has ample support from both obser- ternational Journal of Astronomy and As- vations and simulations of galaxies in clusters. Some, but not all of the obser- trophysics, 11, 95-132. vations and simulations show a phase of increased star formation compared https://doi.org/10.4236/ijaa.2021.111007 to normal spirals. Examples of galaxies undergoing RPS induced star forma- Received: January 30, 2021 tion in clusters experiencing a merger have been identified in high resolution Accepted: March 23, 2021 optical images supporting the existence of a star formation phase. We have Published: March 26, 2021 selected Abell 3266 to search for ram-pressure induced star formation as a global property of a merging cluster. Abell 3266 (z = 0.0594) is a high mass Copyright © 2021 by author(s) and Scientific Research Publishing Inc. cluster that features a high velocity dispersion, an infalling subcluster near to This work is licensed under the Creative the line of sight, and a strong shock front. -
Métodos De Aprendizaje Automático Aplicados a Problemas
UNIVERSIDAD NACIONAL DE CORDOBA´ Facultad de Matematica,´ Astronom´ıa y F´ısica TESIS DE DOCTORADO EN ASTRONOM´IA METODOS´ DE APRENDIZAJE AUTOMATICO´ APLICADOS A PROBLEMAS COSMOLOGICOS´ . AUTOR:LIC.MART´IN EMILIO DE LOS RIOS DIRECTORES:DR.MARIANO JAVIER DOM´INGUEZ Metodos´ de aprendizaje automatico´ aplicados a Problemas Cosmologicos´ por Mart´ın Emilio de los Rios se distribuye bajo una Licencia Creative Commons Atribucion´ 4.0 Internacional. I II 0.1. Palabras claves. Materia Oscura Cumulos´ de galaxias. Cosmolog´ıa. Aprendizaje Automatico.´ 0.2. Clasificaciones 02.70.Rr General statistical methods. 98.65.Cw Galaxy Clusters. 98.80.Es Observational cosmology. 95.35.+d Dark matter (stellar, interstellar, galactic, and cosmological). 95.36.+x Dark energy. III IV Los vicios de la humanidad demuestran lo poco que soy. Agradecimientos A mis viejos, Monica´ y Jorge por el apoyo incondicional. A mis hermanos, Macarena y Diego, porque sin saberlo me ensenan˜ cada d´ıa algo nuevo. A mis sobrinos, Valentina, Juan Lucas, Pietro, Teodelina y Felipe, por alegrar cada instante con sus sonrisas. A mis amigos, por hacer que el d´ıa a d´ıa no sea rutina. A mi director, Mariano Dominguez,´ por el buen humor, las ganas, la paciencia y, so- bretodo, uno que otro pick-and-roll. A mi abuela ‘nani’y mi amiga ‘tito’, por que aunque no las vea me ayudan a continuar. A todos mis colegas del IATE, por brindarme su ayuda y apoyo en todo momento y hacer de este instituto un hermoso lugar de trabajo. V VI Resumen. En este trabajo presentaremos el estudio de diferentes problemas cosmologicos´ me- diante la implementacion´ de tecnicas´ de aprendizaje automatico.´ En la primera parte de la tesis se presenta el marco teorico´ necesario para estudiar los diferentes problemas cos- mologicos´ que abordamos durante la tesis. -
A Catalogue of Zeldovich Pancakes
A Catalogue of Zeldovich Pancakes Mikkel O. Lindholmer Supervisor: Steen H. Hansen Master’s thesis, submitted on October 18, 2015 Dark Cosmology Centre, Niels Bohr Institute, Juliane Maries Vej 30, 2100 Copenhagen, Denmark Abstract Using the standard cold dark matter model ΛCDM, it is predicted that there will be small fluctuations in the primordial energy density. These fluctuations are expected to lead to a cosmic web [1] under the influence of gravity and time. This web will consist of dense galaxy clusters interlinked by less dense two-dimensional walls, so called Zeldovich pancakes [2], and one-dimensional filaments. Galaxy clusters and filaments have been observed for a long time, but only recently have Zeldovich pancakes been observed outside of simulations [6]. The reason these have only recently been observed is because they are much less dense than filaments and clusters, to the point of being hard to differentiate from the average density of their environs [4,5]. Using the method we invented in Falco et. al [6] to find 2 pancakes as a basis, I create a fully automatic program capable of finding pancakes without human input, in galaxy cluster widely different from each other. I apply this program to the Abell galaxy clusters and using the SDSS catalogue I check for potential pancakes in the galaxy clusters. While most of the cluster are contained in the SDSS many of the clusters are only partially covered. I try to make the program compensate for this and manage to create the first catalogue of Zeldovich pancakes by finding 197 of them in 113 different clusters. -
Dynamics of Abell 3266-I. an Optical View of a Complex Merging Cluster
MNRAS 000,1{11 (2016) Preprint 9 March 2017 Compiled using MNRAS LATEX style file v3.0 Dynamics of Abell 3266 { I. An Optical View of a Complex Merging Cluster Siamak Dehghan,1;2? Melanie Johnston-Hollitt,1;2 Matthew Colless3 and Rowan Miller1 1School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6140, New Zealand 2Peripety Scientific Ltd., P.O. Box 11355, Manners Street, Wellington 6142, New Zealand 3Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611, Australia Accepted XXX. Received YYY; in original form ZZZ ABSTRACT We present spectroscopy of 880 galaxies within a 2-degree field around the massive, merging cluster Abell 3266. This sample, which includes 704 new measurements, was combined with the existing redshifts measurements to generate a sample of over 1300 spectroscopic redshifts; the largest spectroscopic sample in the vicinity of A3266 to date. We define a cluster sub-sample of 790 redshifts which lie within a velocity range of 14,000 to 22,000 km s−1and within 1 degree of the cluster centre. A detailed structural analysis finds A3266 to have a complex dynamical structure containing six groups and filaments to the north of the cluster as well as a cluster core which can be decomposed into two components split along a northeast-southwest axis, consistent with previous X-ray observations. The mean redshift of the cluster core is found to be 0:0594±0:0005 +99 −1 and the core velocity dispersion is given as 1462−99 km s . The overall velocity dis- +67 −1 persion and redshift of the entire cluster and related structures are 1337−67 km s and 0:0596 ± 0:0002, respectively, though the high velocity dispersion does not represent virialised motions but rather is due to relative motions of the cluster components. -
ABELL 3266: a Complex Merging Cluster
ABELL 3266: A Complex Merging Cluster Siamak Dehghan, Melanie Johnston-Hollitt, Matthew Colless, and Rowan Miller Horologium-Reticulum Supercluster Redshift 0.06 Length 550 Mly 10^17 solar Mass masses No of 34 Clusters No of 5000 Groups No of Large 30000 Galaxies No of Dwarf 300000 Galaxies No of Stars 10^15 Fleenor et al., The Astronomical Journal, 130, pp. 957-967 Horologium-Reticulum Supercluster Redshift 0.06 Length 550 Mly 10^17 solar Mass masses No of 34 Clusters No of 5000 Groups No of Large 30000 Galaxies No of Dwarf 300000 Galaxies No of Stars 10^15 Fleenor et al., The Astronomical Journal, 130, pp. 957-967 Image Credit: Michael Hudson and Russell Smith and Gemini Observatory A3266: General Properties • Located at the bottom of the HRS, at about 250 Mly away in constellation Reticulum. • One of the largest clusters in the southern hemisphere with hundreds of galaxies, most of which are red ellipticals. • A merging system; elongated X-ray emission from the ICM and high velocity dispersion. What is going on? Abell 3266 is known to be a merging system. However, detailed structure analysis of the cluster has been somewhat hindered due to the lack of sufficient spectroscopic redshifts. Although most of the previous studies note the existence of substructure, there are some disagreements on the exact merger status of the cluster; explicitly, there is a lack of consensus about the phase of the core passage (pre- or post- merger) and the current direction of the cluster and subcluster motions. Spectroscopic Observation In this work we attempt to clarify the dynamical situation in A3266 using optical analysis.