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Illuminating dark sirens with CSST

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Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 165-165页

作者： zong-hong zhu School of Physics and Technology Wuhan UniversityWuhan 430072China Department of Astronomy Beijing Normal UniversityBeijing 100875China

In recent years, the Hubble tension has emerged as one of the most perplexing enigmas within the realm of cosmology[1]. This incongruity suggests the tantalizing prospect of new physics beyond the standard ΛCDM model, leading to the proposal of diverse extended cosmological models. At the same time, there is a pressing demand for novel cosmological tools to mediate the Hubble tension. The gravitational-wave(GW) standard siren has been put forth as a promising cosmological probe for resolving the Hubble tension, provided that the redshift of the GW source is known, as exemplified in ref. [2].

关键词： gravitational source beyond

Erratum to:Detecting gravitational wave with an interferometric seismometer array on lunar nearside[***.66,109513(2023)]

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 182-183页

作者： Junlang Li Fangfei Liu Yuan Pan Zijian Wang Mengdi Cao Mengyao Wang Fan Zhang Jinhai Zhang zong-hong zhu Department of Astronomy Beijing Normal UniversityBeijing 100875China Advanced Institute of Natural Sciences Beijing Normal University at ZhuhaiZhuhai 519087China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Engineering Laboratory for Deep Resources Equipment and Technology Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China

This paper"Detecting gravitational wave with an interferometric seismometer array on lunar nearside"[1]was published in SCIENCE CHINA Physics,Mechanics&Astronomy(66,109513(2023),doi:10.1007/s11433-023-2179-9).Due to an oversight on our part,some errors were made in the originally published *** apologize for these errors and offer the corresponding explanations and corrections for the readers.

关键词： gravitational seism wave

Strongly Lensed Transient Sources:A Review

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Chinese Physics Letters 2022年第11期39卷 72-91页

作者： Kai Liao Marek Biesiada zong-hong zhu School of Physics and Technology Wuhan UniversityWuhan 430072China National Centre for Nuclear Research Pasteura 702-093 WarsawPoland Department of Astronomy Beijing Normal UniversityBeijing 100875China

The past decades have witnessed a lot of progress in gravitational lensing with two main targets:stars and galaxies(with active galactic nuclei).The success is partially attributed to the continuous luminescence of these sources making the detection and monitoring relatively *** the running of ongoing and upcoming large facilities/surveys in various electromagnetic and gravitational-wave bands,the era of time-domain surveys would guarantee constant detection of strongly lensed explosive transient events,for example,supernovae in all types,gamma ray bursts with afterglows in all bands,fast radio bursts,and even gravitational *** transients have many advantages over the traditional targets in studying the Universe,and magnification effect helps to understand the transients themselves at high *** this review article,on base of the recent achievements in literature,we summarize the methods of searching for different kinds of lensed transient signals,the latest results on detection and their applications in fundamental physics,astrophysics,and *** the same time,we give supplementary comments as well as prospects of this emerging research direction that may help readers who are interested in entering this field.

关键词： gravitational galaxies stars

Detecting gravitational wave with an interferometric seismometer array on lunar nearside

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Science China(Physics,Mechanics & Astronomy) 2023年第10期66卷 203-223页

Our Moon is by far the easiest natural, extraterrestrial celestial object for us to reach, and many space agencies, in particular the China National Space Administration, have publicized plans for manned missions there. Such high-profile projects must yield commensurate scientific outputs to justify their cost to the taxpayers. An important criterion for the selection of candidate experiments is the extent to which the Moon plays an integral and irreplaceable role, as opposed to offering only marginal advantages over Earth-orbit, space-based alternatives. In this study, we propose an experiment that excels in this regard, which considers the Moon as part of the experimental apparatus. Specifically, the Moon acts as a Weber bar-style resonant mass that responds to deci-Hertz gravitational waves(GWs). GW-excited lunar vibrations can be picked up by an array of(prefabricated on Earth and easy to transport to the Moon) small laser interferometric seismometers yielding GW detection. Such a setup would plug a gap in the GW frequency range already covered by the existing or underdevelopment detectors, and it can inform us on important astrophysics topics, such as the progenitors of Type Ia supernovae(SNe Ia) or intermediate mass black holes. We provide the instrument design as well as its deployment strategy, and we also summarize relevant science cases according to the estimated viable sensitivity.

关键词： gravitational waves lunar antenna seismic motion

Combining optical and X-ray observations of galaxy clusters to constrain cosmological parameters

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Research in Astronomy and Astrophysics 2011年第7期11卷 776-786页

作者： Heng Yu zong-hong zhu Department of Astronomy Beijing Normal University Beijing 100875 China

Galaxy clusters present unique advantages for cosmological *** we collect a new sample of 10 lensing galaxy clusters with X-ray observations to constrain cosmological *** redshifts of the lensing clusters lie between 0.1 and 0.6,and the redshift range of their arcs is from 0.4 to *** clusters are selected carefully from strong gravitational lensing systems which have both X-ray satellite observations and optical giant luminous arcs with known *** arcs usually appear in the central region of clusters,where mass can be traced with luminosity quite *** on gravitational lensing theory and a cluster mass distribution model,we can derive a ratio using two angular diameter *** is the distance between lensing sources and the other is that between the deflector and the source. Since angular diameter distance relies heavily on cosmological geometry,we can use these ratios to constrain cosmological ***,X-ray gas fractions of galaxy clusters can also be a cosmological *** there are a dozen parameters to be fitted,we introduce a new analytic algorithm,Powell＇s UOBYQA（Unconstrained Optimization By Quadratic Approximation） ,to accelerate our *** result demonstrates that this algorithm is an effective fitting method for such a continuous multi-parameter *** find an interesting fact that these two approaches are separately sensitive toΩΛandΩ*** combining them,we can get reasonable fitting values of basic cosmological parameters：ΩM=0.26 ＋0.04 -0.04,andΩΛ=0.82 ＋0.14 -0.16.

关键词： X-rays:galaxies:clusters—gravitational lensing—cosmological parameters

Development and validation of a new prognostic model for patients with acute-on-chronic liver failure in intensive care unit

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World Journal of Gastroenterology 2024年第20期30卷 2657-2676页

作者： zong-Yi zhu Xiu-hong Huang Hui-Qing Jiang Li Liu Department of Gastroenterology The Second Hospital of Hebei Medical UniversityShijiazhuang 050000Hebei ProvinceChina Department of Gastroenterology Weixian People's HospitalXingtai 054700Hebei ProvinceChina

BACKGROUND Cirrhotic patients with acute-on-chronic liver failure(ACLF)in the intensive care unit(ICU)have a poor but variable *** prognosis evaluation can guide the rational management of patients with ***,existing prognostic scores for ACLF in the ICU environment lack sufficient *** To develop a new prognostic model for patients with ACLF in *** Data from 938 ACLF patients in the Medical Information Mart for Intensive Care(MIMIC)database were used to develop a new prognostic model(MIMIC ACLF)for ***,calibration and clinical utility of MIMIC ACLF were assessed by area under receiver operating characteristic curve(AUROC),calibration curve and decision curve analysis(DCA),*** ACLF was then externally validated in a multiple-center cohort,the Electronic Intensive Care Collaborative Research Database and a single-center cohort from the Second Hospital of Hebei Medical University in *** The MIMIC ACLF score was determined using nine variables:ln(age)×2.2+ln(white blood cell count)×0.22-ln(mean arterial pressure)×2.7+respiratory failure×0.6+renal failure×0.51+cerebral failure×0.31+ln(total bilirubin)×0.44+ln(internationalized normal ratio)×0.59+ln(serum potassium)×*** MIMIC cohort,the AUROC(0.81/0.79)for MIMIC ACLF for 28/90-day ACLF mortality were significantly greater than those of Chronic Liver Failure Consortium ACLF(0.76/0.74),Model for End-stage Liver Disease(MELD;0.73/0.71)and MELD-Na(0.72/0.70)(all P<0.001).The consistency between actual and predicted 28/90-day survival rates of patients according to MIMIC ACLF score was excellent and superior to that of existing *** net benefit of MIMIC ACLF was greater than that achieved using existing scores within the 50%threshold *** superior predictive accuracy and clinical utility of MIMIC ACLF were validated in the external *** We developed and validated a new prognostic model with satisfactory accuracy

关键词： Acute-on-chronic liver failure Cirrhosis Risk stratification Prognosis Model Scores

“Conserved charges” of the Bondi-Metzner-Sachs algebra in the Brans-Dicke theory

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Chinese Physics C 2021年第2期45卷 377-393页

作者： Shaoqi Hou zong-hong zhu School of Physics and Technology Wuhan UniversityWuhan 430072China Department of Astronomy Beijing Normal UniversityBeijing 100875China

The asymptotic symmetries in the Brans-Dicke theory are analyzed using Penrose's conformal completion method,which is independent of the coordinate system *** symmetries,indeed,include supertranslations and Lorentz transformations for an asymptotically flat *** the Wald-Zoupas formalism,“conserved charges”and fluxes of the Bondi-Metzner-Sachs algebra are *** scalar degree of freedom contributes only to the Lorentz boost charge,even though it plays a role in various *** flux-balance laws are further applied to constrain the displacement memory,spin memory,and center-of-mass memory effects.

关键词： Bondi-Metzner-Sachs symmetry conserved charges Brans-Dicke theory gravitational waves memory effects

Observational constraints on the new generalized Chaplygin gas model

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Research in Astronomy and Astrophysics 2013年第2期13卷 159-169页

作者： Kai Liao Yu Pan zong-hong zhu Department of Astronomy Beijing Normal University

We use the latest data to investigate observational constraints on the new generalized Chaplygin gas （NGCG） model. Using the Markov Chain Monte Carlo method, we constrain the NGCG model with type Ia supernovae from the Union2 set （557 data）, the usual baryonic acoustic oscillation （BAO） observation from the spectroscopic Sloan Digital Sky Survey data release 7 galaxy sample, the cosmic mi- crowave background observation from the 7-year Wilkinson Microwave Anisotropy Probe results, newly revised data on H（z）, as well as a value of θBAO （Z = 0.55） = （3.90° ±0.38°） for the angular BAO scale. The constraint results for the NGCG model are ωX=-1.0510＋0.1563-0.1685（1σ）＋0.2226-0.2398（2σ）,η=1.0117＋0.0469-0.0502（1σ）＋0.0693-0.0716（2σ）and ΩX=0.7297＋0.0229-0.0276（1σ）＋0.0329-0.0402（2σ）, which give a rather stringent constraint. From the results, we can see that a phantom model is slightly favored and the proba- bility that energy transfers from dark matter to dark energy is a little larger than the inverse.

关键词： new generalized Chaplygin gas -- angular BAO scale -- cosmologicalobservations

A multi-wavelength study of the gravitational lens COSMOS J095930+023427

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Research in Astronomy and Astrophysics 2013年第1期13卷 15-27页

作者： Shuo Cao Giovanni Covone Maurizio Paolillo zong-hong zhu Department of Astronomy Beijing Normal University Dipartimento di Scienze Fisiche Universita` di Napoli "Federico II" Complesso Universitario di Monte S.Angelo INFN Sezione di NapoliComplesso Universitario di Monte S.Angelo

We present a multi-wavelength study of the gravitational lens COSMOS J095930＋023427 （Zl = 0.892）, together with the associated galaxy group along the line of sight located at z 0.7, and the lensed background galaxy. The source redshift is currently unknown, but estimated to be at zs ~ 2. This analysis is based on publicly available HST, Subaru and Chandra imaging data, as well as VLT spectroscopy. The lensing system is an early-type galaxy showing a strong [OII] emission line, and pro- duces four bright images of the distant background source. It has an Einstein radius of 0.79＂, about four times larger than the effective radius. We perform a lensing anal- ysis using both a singular isothermal ellipsoid and a peudo-isothermal elliptical mass distribution for the lensing galaxy, and find that the final results on the total mass, the dark matter （DM） fraction within the Einstein radius and the external shear due to a foreground galaxy group are robust with respect to the choice of the parametric model and the source redshift （yet unknown）. We measure the luminous mass from the pho- tometric data, and find the DM fraction within the Einstein radius fDM to be between 0.71 ~ 0.13 and 0.79 ~ 0.15, depending on the unknown source redshift. Meanwhile, the non-null external shear found in our lensing models supports the presence and structure of a galaxy group at z ~ 0.7, and an independent measurement of the 0.5- 2 keV X-ray luminosity within 20＂ around the X-ray centroid provides a group mass of M = （3 - 10） x 1013 Mo, in good agreement with the previous estimate derived through weak lensing analysis. Finally, by inverting the HST/ACS/814 image with the lensing equation, we obtain the reconstructed image of the magnified source galaxy, which has a scale of about 3.3 kpc at z~ = 2 （2.7 kpc at zs = 4） and the typical disturbed disk-like appearance observed in low-mass star-forming galaxies at z ~ 3. However, deep, spatially resolved spectroscopic data for similar lensed sour

关键词： galaxies: individual (COSMOS J095930+023427) -- gravitational lens-ing -- dark matter