Upcoming Journal Club

Dr. Yong Tian: "A massive blow for ΛCDM - the high redshift, mass, and collision velocity of the interacting galaxy cluster El Gordo contradicts concordance cosmology [Online via Zoom due to the current alert of covid-19]"

Time/Location: 2021-06-09 12:10 [Zoom]

Authers/Journal Paper:

Abstract:

El Gordo (ACT-CL J0102-4915) is an extremely massive galaxy cluster (M200 ≍ 3 × 1015 M⊙) at redshift z = 0.87 composed of two subclusters with a mass ratio of 3.6 merging at speed Vinfall ≍ 2500 km s-1. Such a fast collision between individually rare massive clusters is unexpected in Lambda cold dark matter (ΛCDM) cosmology at such high z. However, this is required for non-cosmological hydrodynamical simulations of the merger to match its observed properties. Here, we determine the probability of finding a similar object in a ΛCDM context using the Jubilee simulation box with a side length of 6h−1 Gpc. We search for galaxy cluster pairs that have turned around from the cosmic expansion with properties similar to El Gordo in terms of total mass, mass ratio, redshift, and collision velocity relative to virial velocity. We fit the distribution of pair total mass quite accurately, with the fits used in two methods to infer the probability of observing El Gordo in the surveyed region. The more conservative (and detailed) method involves considering the expected distribution of pairwise mass and redshift for analog pairs with similar dimensionless parameters to El Gordo in the past light-cone of a z = 0 observer. Detecting one pair with its mass and redshift rules out ΛCDM cosmology at 6.16σ. We also use the results of Kraljic and Sarkar to show that the Bullet Cluster is in 2.78σ tension once the sky coverage of its discovery survey is accounted for. Using a χ2 approach, the combined tension can be estimated as 6.43σ. Both collisions arise naturally in a Milgromian dynamics (MOND) cosmology with light sterile neutrinos.
For more details, you may refer to the link: https://ui.adsabs.harvard.edu/abs/2021MNRAS.500.5249A/abstract

We will meet here on Zoom:
https://zoomtw.zoom.us/j/97756079510?pwd=c3VjQ0diSWV4YkpIT0IzL283S1VBUT09
ID: 977 5607 9510
Password: astro


Journal Club List

DateSpeakerTitle
2021-06-09Dr. Yong TianA massive blow for ΛCDM - the high redshift, mass, and collision velocity of the interacting galaxy cluster El Gordo contradicts concordance cosmology [Online via Zoom due to the current alert of covid-19]
2021-06-02Prof. Shin-Shan YuSearch for dark matter with the mono-h channel at CMS [Online via Zoom due to the current alert of covid-19]
2021-05-26Prof. Ling-Hsiao LyuVelocity-shear instabilities and their future applications to the unsolved problems in astrophysics [Online via Zoom due to the current alert of covid-19]
2021-05-19Tanvi SharmaWD1032 + 011, an inflated brown dwarf in an old eclipsing binary with a white dwarf [Online via Zoom due to the current alert of covid-19]
2021-05-12Dr. Jhen-Yu ChenSelf-consistent Color-Stellar Mass-to-light Ratio Relations for Low Surface Brightness Galaxies
2021-05-05Prof. KinoshitaBasic Photometry Techniques
2021-04-28Prof. PanThe interacting nature of dwarf galaxies hosting superluminous supernovae
2021-04-14Bhavana LalchandK-band High-Resolution Spectroscopy of Embedded High-Mass Protostars
2021-03-31Prof. IpUranian satellite formation by evolution of a water vapour disk generated by a giant impact
2021-03-24Prof. NgeowThe Accuracy of the Hubble Constant Measurement Verified through Cepheid Amplitudes
2021-03-17Prof. ChouWhat’s new on neutron stars?
2021-03-10Prof. HwangGW190521 as a merger of Proca stars: a potential new vector boson of 8.7×10−13 eV
2020-12-30Prof. Pan"First Hubble diagram and cosmological constraints using superluminous supernova" by Inserra et al.
2020-12-23Prof. Chen"Discovery of a mid-infrared protostellar outburst of exceptional amplitude" by Lucas et al.
2020-12-09Prof. Hwang"Apparent evidence for Hawking points in the CMB Sky" by Daniel An, Krzysztof A. Meissner, Paweł Nurowski and Roger Penrose
2020-12-02Dr. Yong TianMass-Velocity Dispersion Relation in HIFLUGCS Galaxy Clusters
2020-11-11Prof. IpA tadpole's metamorphosis
2020-10-28Dr. Ying LiaoSublimation as an effective mechanism for flattened lobes of (486958) Arrokoth
2020-10-21Prof. NgeowThe value of the Hubble-Lemaître constant queried by Type Ia Supernovae: A journey from the Calán-Tololo Project to the Carnegie Supernova Program
2019-12-19Prof. Chen Wen-PingAnnual Review of Astronomy and Astrophysics 2019
2019-12-05Dr. Kinoshita DaisukeMy plan for coming winter vacation - observations of comet 289P/Blanpain
2019-11-28Dr. Zhong-Yi Lin Comets and Interstellar objects
2019-11-21Dr. Chow-Choong NgeowHow to Write A (Good) LOT Proposal
2019-10-17Prof. Ip Wing-HuenTen Easy Pieces
2019-10-03Dr. Hwang Chorng-YuanConfirmation of Planet-Mass Objects in Extragalactic Systems
2018-12-24Prof. Chorng-Yuan HwangGalaxy cluster mergers as triggers for the formation of jellyfish galaxies: case study of the A901/2 system
2018-12-17Prof. Wen-Ping ChenCould Solar Radiation Pressure Explain ‘Oumuamua’s Peculiar Acceleration?
2018-12-10Chia-Lung LinDetecting Water in the Atmosphere of HR 8799 c with L-band High-dispersion Spectroscopy Aided by Adaptive Optics
2018-11-26Dr. Chiende LeeVelocity-resolved [O I] 63 μm Emission in the HD 50138 Circumstellar Disk
2018-11-19Dr. Yong TianUltra Diffuse Galaxy NGC1052–DF2 lacking Dark Matter?
2018-06-13Dr. Ngeow, Chow-ChoongGaia Data Release 2: Observational Hertzsprung-Russell diagrams
2018-06-06Professor Chung-Ming KoSignal coverage approach to the detection probability of hypothetical extraterrestrial emitters in the Milky Way
2018-05-30Nai-Hui LiaoThe expected spins of gravitational wave sources with isolated field binary progenitors
2018-05-16Jia-Yu OuMira Variable Stars from LAMOST DR4 Data: Emission Features, Temperature Types, and Candidate Selection
2018-05-02Dr. Daisuke KinoshitaDome C ultracarbonaceous Antarctic micrometeorites. Infrared and Raman fingerprints
2018-04-25Po-Chieh YuA density cusp of quiescent X-ray binaries in the central parsec of the Galaxy
2018-04-11Han Zheng 鄭翰Unveiling the Origin of the Fermi Bubbles
2018-03-28Tsan-Ming Wang 王贊銘Metal Deficiency in Two Massive Dead Galaxies at z ~ 2
2018-01-16Po-Shih ChiangIDENTIFYING EXOPLANETS WITH DEEP LEARNING: A FIVE PLANET RESONANT CHAIN AROUND KEPLER-80 AND AN EIGHTH PLANET AROUND KEPLER-90
2018-01-09Dr. Chan-Kao ChangA binary main-belt comet
2017-11-28Bhavana LalchandA brief visit from a red and extremely elongated interstellar asteroid
2017-11-21Prof. Yi ChouThe Neutron star Interior Composition ExploreR (NICER): an Explorer mission of opportunity for soft x-ray timing spectroscopy
2017-11-14Prof. Chow-Choong NgeowHunting the Optical Counterparts for Gravitational Wave Events
2017-10-31Chia-Hsiang Huang The mean star formation rates of unobscured QSOs: searching for evidence of suppressed or enhanced star formation
2017-10-24Prof. Wing-Huen IpIlluminating gravitational waves: A concordant picture of photons from a neutron star merger
2017-10-17Prof. Chorng-Yuan HwangHow large are the globular cluster systems of early-type galaxies and do they scale with galaxy halo properties?
2017-10-03Prof. Wen-Ping ChenAnnual Review of Astronomy and Astrophysics 2017
2017-06-08Hung-En HsienDiscovery of a soft X-ray 8 mHz QPO from the accreting millisecond pulsar IGR J00291+5934
2017-06-01Yi-Hao SuMaking Your Astronomy Research Code Citable
2017-05-11Dr. Daisuke KinoshitaThe Splitting of Double-component Active Asteroid P/2016 J1 (PANSTARRS)
2017-05-04Dr. Po-Chieh YuGROWTH OF BULGES IN DISC GALAXIES SINCE Z ∼ 1
2017-04-20Prof. Wen-Ping ChenSpiral density waves in a young protoplanetary disk
2017-04-06Jen-Chao HuangHiding in Plain Sight - Recovering Clusters of Galaxies with the Strongest AGN in Their Cores Tucanae
2017-03-30Prof. Wing-Huen IpRepeating fast radio bursts from highly magnetized pulsars traveling through asteroid belts
2017-02-16Dr. Chien-De LeeAn intermediate-mass black hole in the centre of the globular cluster 47 Tucanae
2016-12-15Dr. Yu-Chi ChengDiscovery of a New Retrograde Trans-Neptunian Object: Hint of a Common Orbital Plane for Low Semimajor Axis, High-inclination TNOs and Centaurs
2016-12-08Prof. Yi ChouDiscovery of a new accreting millisecond X-ray pulsar in the globular cluster NGC 2808
2016-11-24Hsing-Wen LinConsequences of a Distant Massive Planet on the Large Semi-major Axis Trans-Neptunian Objects
2016-10-20Po-Shih ChiangSpiral density waves in a young protoplanetary disk
2016-10-13Chien-De LeePan-STARRS and PESSTO search for an optical counterpart to the LIGO gravitational-wave source GW150914
2016-05-26Jen-Chao HuangRadio continuum detection in blue early-type weak emission line galaxies
2016-05-12Dr. Chan-Kao ChangA 2 km-size asteroid challenging the rubble-pile spin barrier - A case for cohesion
2016-04-28 Manash Ranjan SamalEpisodic molecular outflow in the very young protostellar cluster Serpens South
2016-04-21Po-Chieh YuALMA resolves the torus of NGC 1068: continuum and molecular line emission
2016-04-07Prof. Wen-Ping ChenWISEA J114724.10-204021.3: A Free-Floating Planetary Mass Member of the TW Hya Association
2016-03-10Chien-De LeeProperties of the binary black hole merger GW150914
2016-02-25Po-Shih Chiang 姜博識An all-sky Support Vector Machine selection of WISE YSO Candidates.
2015-12-31Prof. Yi Chou 周翊A possible cyclotron resonance scattering feature near 0.7 keV in X1822-371
2015-12-10Yong Tian 田雍Statistical Method on Astrophysics – Local Regression Method
2015-11-26Daisuke Kinoshita 木下大輔Observations of “fresh” and weathered surfaces on asteroid pairs and their implications on the rotational-fission mechanism
2015-10-29Yu-Chi Cheng 鄭宇棋The NEOWISE-Discovered Comet Population and the CO+CO2 production rates
2015-10-08Po-Shih Chiang 姜博識Discovery and spectroscopy of the young Jovian planet 51 Eri b with the Gemini Planet Imager
2015-10-01Hsing-Wen Lin 林省文Space Weathering Trends Among Carbonaceous Asteroids
2015-05-29Daisuke Kinoshita 木下大輔Spectral properties of the largest asteroids associated with Taurid Complex
2015-05-14Chan-Kao Chang 章展誥29 November 2011 stellar occultation by 2060 Chiron: Symmetric jet-like features
2015-04-30I-Ling Lin 林怡伶Ongoing hydrothermal activities within Enceladus
2015-04-09Dr. Hsing-Wen Lin 林省文Planet heating prevents inward migration of planetary cores
2015-03-19Yong Tian 田雍Dynamics of Elliptical Galaxies with Planetary Nebulae in the MOdified Newtonian Dynamics
2015-01-08Yi-Hao Su 蘇羿豪Practices in source code sharing in astrophysics
2014-12-25I-Ling Lin 林怡伶The Secret Lives of Cepheids: Evolutionary Changes and Pulsation-Induced Shock Heating in the Prototype Classical Cepheid δ Cep
2014-12-18I-Chenn Chen 陳以忱J1649+26: A Grand-Design Spiral with a Large Double-Lobed Radio Source
2014-12-04Ting-Chang Yang 楊庭彰SDSS J001153.08-064739.2, a Cataclysmic Variable with an Evolved Donor in the Period Gap
2014-11-27Li-Ching Huang 黃立晴Kepler Flares I. Active and Inactive M dwarfs
2014-11-06Chien-De Lee 李建德How tiny galaxies form stars
2014-10-30Jen-Chao Huang 黃仁昭Relics of Galaxy Merging: Observational Predictions for a Wandering Massive Black Hole and Accompanying Star Cluster in the Halo of M31
2014-10-16Yu-Chi Cheng 鄭宇棋Dust environment and dynamical history of a sample of short-period comets
2014-10-09Zong-Fu Sie 謝宗富The host galaxy and late-time evolution of the Super-Luminous Supernova PTF12dam
2014-10-02Po-Shin Chiang 姜博識Gender-based Systematics in HST Proposal Selection
2014-06-05Yi-Hao SuBlack hole spin measurements through the relativistic precession model: XTE J1550-564
2014-05-29Po-Chieh YuNASA's WISE Findings Poke Hole in Black Hole 'Doughnut' Theory
2014-05-15An-Li TsaiSuppression of star formation in the galaxy NGC 253 by a starburst-driven molecular wind
2014-05-08Chan-Kao ChangA ring system detected around the Centaur (10199) Chariklo
2014-05-01Ching-Ping LinFound: the progenitors of AM CVn and supernovae .Ia
2014-04-24Ting-Chang YangA millisecond pulsar in a stellar triple system
2014-03-27Hsing-Wen LinDark Matter as a trigger for Periodic Comet Impacts
2014-03-20Zhong-Yi LinThe water production rate of Rosetta target Comet 67P/Churyumov-Gerasimenko near perihelion in 1996, 2002 and 2009 from Lyman α observations with SWAN/SOHO
2014-03-13Daisuke KinoshitaThe internal structure of asteroid (25143) Itokawa as revealed by detection of YORP spin-up
2014-03-06Po-Shih ChiangA global cloud map of the nearest known brown dwarf
2014-01-09Yu-Chi ChengTHE DISCOVERY OF COMETARY ACTIVITY IN NEAR-EARTH ASTEROID (3552) DON QUIXOTE
2014-01-02Yi ChouSwings between rotation and accretion power in a binary millisecond pulsar
2013-12-26Chien-Cheng LinEvaluating Gyrochronology on the Zero-Age-Main-Sequence: Rotation Periods in the Southern Open Cluster Blanco 1 from the KELT-South Survey
2013-12-19Zong-Fu SieTHE SMALL NUMBERS OF LARGE KUIPER BELT OBJECTS
2013-12-12I-Chenn ChenStar formation and AGN activity in interacting galaxies: a near-UV perspective
2013-12-05Chin-Ping HuA long-term X-ray monitoring of the ultraluminous X-ray source NGC 5408 X-1 with Swift reveals the presence of dips but no orbital period
2013-11-28Li-Ching HuangA rocky composition for an Earth-sized exoplanet
2013-11-28Lin TuA high-amplitude thermal inertia anomaly of probable magnetospheric origin on Saturn’s moon Mimas
2013-10-31Wen-Ping ChenA SCUBA-2 850-μm survey of protoplanetary discs in the σ Orionis cluster
2013-10-24Jen-Chao HuangA high Eddington-ratio, true Seyfert 2 galaxy candidate: implications for broad-line region models
2013-10-03Chandler LeeA study of Be stars in the Magellanic Clouds
2013-09-25Prof. Wing-Huen IpIn Situ Observations of Interstellar Plasma With Voyager 1