Publications (70)
Design and Validation of the Digital Receiver System for the next-generation radio interferometer
Donghao Qu, Jiajun Zhang, Yajun Wu +3
This paper presents the design and validation of a digital receiver system developed for the next-generation radio interferometer projects. The receiver supports 8 analog inputs wi…
An extended stellar halo discovered in the Fornax dwarf spheroidal using Gaia EDR3
Yanbin Yang, Francois Hammer, Yongjun Jiao +1
We have studied the extent of the Red Giant Branch stellar population in the Fornax dwarf spheroidal galaxy using the spatially extended and homogeneous data set from Gaia EDR3. Ou…
Gaia EDR3 proper motions of Milky Way dwarfs. II: Velocities, Total Energy and Angular Momentum
François Hammer, Jianling Wang, Marcel Pawlowski +5
Here we show that precise Gaia EDR3 proper motions have provided robust estimates of 3D velocities, angular momentum and total energy for 40 Milky Way dwarfs. The results are stati…
The NGC 4013 tale: a pseudo-bulged, late-type spiral shaped by a major merger
Jianling Wang, Francois Hammer, Mathieu Puech +2
Many spiral galaxy haloes show stellar streams with various morphologies when observed with deep images. The origin of these tidal features is discussed, either coming from a satel…
Most dwarf spheroidal galaxies surrounding the Milky Way cannot be dark-matter dominated satellites
Francois Hammer, Yanbin Yang, Frederic Arenou +5
Milky Way dwarf spheroidal galaxies are the tiniest observed galaxies and are currently associated with the largest fractions of dark matter, which is revealed by their too large v…
WLM: Dynamics of an isolated Dwarf Irregular Galaxy Under Ram Pressure in the Local Group
Neel Kolhe, Francois Hammer, Yanbin Yang +5
WLM is an archetypal dwarf irregular galaxy that has not experienced interactions with major Local Group galaxies within the past 8 Gyr. It has recently been shown that WLM is losi…
Two substructures in the nearby stellar halo found in Gaia and RAVE
Hefan Li, Cuihua Du, Yanbin Yang +4
We use the second Gaia data release (Gaia DR2), combined with RAVE spectroscopic surveys, to identify the substructures in the nearby stellar halo. We select 3,845 halo stars kinem…
A Potential Dynamical Origin of The Galactic Disk Warp: The Gaia-Sausage-Enceladus Major Merger
Mingji Deng, Cuihua Du, Yanbin Yang +2
Previous studies have revealed that the Galactic warp is a long-lived, nonsteady, and asymmetric structure. There is a need for a model that accounts for the warp's long-term evolu…
Milky Way total Mass derived by Rotation Curve and Globular Cluster kinematics from Gaia EDR3
Jianling Wang, Francois Hammer, Yanbin Yang
Using action-based distribution function for the dynamical model of the Milky Way we have estimated its total mass and its density profile. Constraints are coming from the globular…
On the absence of dark matter in dwarf galaxies surrounding the Milky Way
Francois Hammer, Yanbin Yang, Jianling Wang +3
This paper presents an alternative scenario to explain the observed properties of the Milky Way dwarf Spheroidals (MW dSphs). We show that instead of resulting from large amounts o…
Co-orbiting satellite galaxy structures are still in conflict with the distribution of primordial dwarf galaxies
Marcel S. Pawlowski, Benoit Famaey, Helmut Jerjen +11
Both major galaxies in the Local Group host planar distributions of co-orbiting satellite galaxies, the Vast Polar Structure (VPOS) of the Milky Way and the Great Plane of Andromed…
The vast thin plane of M31 co-rotating dwarfs: an additional fossil signature of the M31 merger and of its considerable impact in the whole Local Group
François Hammer, Yanbin Yang, Sylvain Fouquet +5
The recent discovery by Ibata et al. (2013) of a vast thin disk of satellites (VTDS) around M31 offers a new challenge for the understanding of the Local Group properties. This com…
MOSAIC: the high-multiplex and multi-IFU spectrograph for the ELT
Rubén Sánchez-Janssen, Francois Hammer, Simon Morris +40
MOSAIC is the planned multi-object spectrograph for the 39m Extremely Large Telescope (ELT). Conceived as a multi-purpose instrument, it offers both high multiplex and multi-IFU ca…
The accretion history of the Milky Way. I. How it shapes globular clusters and dwarf galaxies
Francois Hammer, Hefan Li, Gary A. Mamon +6
Halo inhabitants are individual stars, stellar streams, star and globular clusters, and dwarf galaxies. Here we compare the two last categories that include objects of similar stel…
Disentangling the morpho-kinematic properties of a face-on merger at z~0.7
Isaura Fuentes-Carrera, Hector Flores, Yanbin Yang +4
At intermediate redshifts, many galaxies seem to be perturbed or suffering from an interaction. Considering that disk galaxies may have formed and evolved through minor mergers or…
The accretion history of the Milky Way V. The kinematics of most globular clusters trace the merger epochs
Istiak Akib, François Hammer, Yanbin Yang
Several studies have associated globular clusters (GCs) with former Galactic accretion events by comparing their positions in the energy-angular momentum (-) plane, an appr…
High sensitivity HI image of diffuse gas and new tidal features in M51 observed by FAST
Haiyang Yu, Ming Zhu, Jin-Long Xu +3
We observed the classical interacting galaxy M51 with FAST and obtain high sensitivity HI image with column density down to 3.8 10 cm. In the image we can se…
The direct oxygen abundances of metal-rich galaxies derived from electron temperature
Y. C. Liang, F. Hammer, S. Y. Yin +3
We aim to derive the electron temperature Te in the gas of metal-rich star-forming galaxies, which can be obtained from their ratios of auroral lines [O II]7320,7330 to nebular lin…
Evolution of Galaxy Luminosity Function and Luminosity Function by Density Environment at 0.03<z<0.5
Lifang Xia, Xu Zhou, Yanbin Yang +2
Using galaxy sample observed by the BATC large-field multi-color sky survey and galaxy data of SDSS in the overlapped fields, we study the dependence of the restframe -band gala…
Merger Dynamics of the Pair of Galaxy Clusters -- A399 and A401
Qirong Yuan, Pengfei Yan, Yanbin Yang +1
Convincing evidence of a past interaction between two rich clusters A399 and A401 was recently found by the X-ray imaging observations. In this paper we examine the structure and d…
Ram-pressure signatures in the dwarf irregular galaxy SextansB revealed by deep MeerKAT HI observations
Brenda Namumba, Neel Kolhe, Francois Hammer +12
The impact of extremely low-density environments such as the diffuse intergalactic medium (IGM) on the neutral gas distribution of dwarf galaxies remains poorly explored observatio…
Performance of the Segment Anything Model in Various RFI/Events Detection in Radio Astronomy
Yanbin Yang, Feiyu Zhao, Ruxi Liang +4
The emerging era of big data in radio astronomy demands more efficient and higher-quality processing of observational data. While deep learning methods have been applied to tasks s…
Considerations on how to investigate planes of satellite galaxies
Marcel S. Pawlowski, Jörg Dabringhausen, Benoit Famaey +11
The existence of a spatially thin, kinematically coherent Disk of Satellites (DoS) around the Milky Way (MW), is a problem that often garners vivacious debate in the literature or…
Tidal origin of dark-matter free dwarf galaxies in the NGC 1052 group
Francois Hammer, Yanbin Yang
Discovery of dark-matter (DM) free dwarf galaxies in the NGC 1052 neighborhood has had a considerable impact on modern cosmology. They have been explained through a dwarf--dwarf he…
The ELT-MOS (MOSAIC): towards the construction phase
Simon Morris, François Hammer, Pascal Jagourel +50
When combined with the huge collecting area of the ELT, MOSAIC will be the most effective and flexible Multi-Object Spectrograph (MOS) facility in the world, having both a high mul…
Kinematics and Stellar Population Properties of the Andromeda Galaxy by the Spectroscopic Observations of the Guoshoujing Telescope
Hu Zou, Yanbin Yang, Tianmeng Zhang +6
The Andromeda galaxy was observed by the Guoshoujing Telescope (GSJT, formly named the Large Sky Area Multi-Object Fiber Spectroscopic Telescope -- LAMOST) during the 2009 commissi…
Large-Field Multicolor Study of Abell 168 : Subclusters, Dynamics and Luminosity Functions
Yanbin Yang, Xu Zhou, Qirong Yuan +4
This paper presents a multicolor study of the nearby cluster of galaxies Abell 168 (z=0.045) with 13 intermediate-band filters in the Beijing-Arizona-Taiwan-Connecticut (BATC) filt…
FAST reveals new evidence for M94 as a merger
Ruilei Zhou, Ming Zhu, Yanbin Yang +4
We report the first high-sensitivity HI observation toward the spiral galaxy M94 with the Five-hundred-meter Aperture Spherical radio Telescope (FAST). From these observations, we…
Reproducing properties of MW dSphs as descendants of DM-free TDGs
Yanbin Yang, Francois Hammer, Sylvain Fouquet +4
The Milky Way (MW) dwarf spheroidal (dSph) satellites are known to be the most dark-matter (DM) dominated galaxies with estimates of dark to baryonic matter reaching even above one…
Color and Metallicity Distributions of M81 Globular Clusters
Jun Ma, Xu Zhou, Jiansheng Chen +4
In this paper we present catalogs of photometric and spectroscopic data for M81 globular clusters (GCs). The catalogs include B- and V- photometric and reddening data of 95 GCs, an…
Lessons from the Magellanic System and its modeling
Jianling Wang, Francois Hammer, Yanbin Yang
The prominent Magellanic Stream that dominates the HI sky provides a tantalizing number of observations that potentially constrains the Magellanic Clouds and the Milky Way outskirt…
The survey of planetary nebulae in Andromeda (M31) VI. Kinematics of M31 inner-halo substructures and comparison with major-merger simulation predictions
Souradeep Bhattacharya, Magda Arnaboldi, Francois Hammer +4
M31 has experienced a recent tumultuous merger history as evidenced from the many substructures that are still present in its inner halo, particularly the G1-Clump, NE- and W- shel…
Accurate Sky Continuum Subtraction with Fibre-fed Spectrographs
Yanbin Yang, Myriam Rodrigues, Mathieu Puech +10
Fibre-fed spectrographs now have throughputs equivalent to slit spectrographs. However, the sky subtraction accuracy that can be reached has often been pinpointed as one of the maj…
A giant bar induced by a merger event at z=0.4?
Sébastien Peirani, Francois Hammer, Hector Flores +2
(Aims) We present a physical model of the formation of J033239.72-275154.7, a galaxy observed at z=0.41 and characterized by a big young bar of size 6 kpc. The study of this system…
Observation of heat scaling across a first-order quantum phase transition in a spinor condensate
Haiyu Liang, Liyuan Qiu, Yanbin Yang +4
Heat generated as a result of the breakdown of an adiabatic process is one of the central concepts of thermodynamics. In isolated systems, the heat can be defined as an energy incr…
A Recent Major Merger Tale for the Closest Giant Elliptical Galaxy Centaurus A
Jianling Wang, Francois Hammer, Marina Rejkuba +2
We have used hydrodynamical simulations to model the formation of the closest giant elliptical galaxy, Centaurus A. We find that a single major merger event with a mass ratio up to…
Morphological Dependence of Star Formation Properties for the Galaxies in the Merging Galaxy Cluster A2255
Qirong Yuan, Lifang Zhao, Yanbin Yang +2
The merging cluster of galaxies A2255 is covered by the Sloan Digital Sky Survey (SDSS) survey. In this paper we perform a morphological classification on the basis of the SDSS ima…
The Formation of Magellanic System and the total mass of Large Magellanic Cloud
Jianling Wang, Francois Hammer, Yanbin Yang +1
The Magellanic Stream is unique to sample the MW potential from ~50 kpc to 300 kpc, and is also unique in constraining the LMC mass, an increasingly important question for the Loca…
The accretion history of the Milky Way. II. Internal kinematics of globular clusters and of dwarf galaxies
Francois Hammer, Jianling Wang, Gary A. Mamon +7
We study how structural properties of globular clusters and dwarf galaxies are linked to their orbits in the Milky Way halo. From the inner to the outer halo, orbital energy increa…
Galactic structure studies with BATC star counts
Cuihua Du, Xu Zhou, Jun Ma +6
We report the first results of star counts carried out with the National Astronomical Observatories (NAOC) 60/90 cm Schmidt Telescope in 15 intermediate-band filters from 3000 to 1…
The Andromeda Galaxy's Last Major Merger: Constraints from the survey of Planetary Nebulae
Souradeep Bhattacharya, Magda Arnaboldi, Ortwin Gerhard +7
The Andromeda galaxy (M 31) has experienced a tumultuous merger history as evidenced by the many substructures present in its inner halo. We use planetary nebulae (PNe) as chemodyn…
The accretion history of the Milky Way IV. Hints of recent star formation in Milky Way dwarf spheroidal galaxies
Yanbin Yang, Elisabetta Caffau, Piercarlo Bonifacio +3
Dwarf spheroidal galaxies are known to be dominated by old stellar populations. This has led to the assumption that their gas-rich progenitors lost their gas during their infall in…
On-sky tests of sky-subtraction methods for fiber-fed spectrographs
Myriam Rodrigues, Michele Cirasuolo, Francois Hammer +8
We present preliminary results on on-sky test of sky subtraction methods for fiber-fed spectrograph. Using dedicated observation with FLAMES/VLT in I-band, we have tested the accur…
Chandra X-ray Analysis of Galaxy Cluster A168
Yanbin Yang, Zhiying Huo, Xu Zhou +4
We present Chandra X-ray observations of galaxy cluster A168 (z=0.045). Two X-ray peaks with a projected distance of 676 kpc are found to be located close to two dominant galaxies,…
Gaia EDR3 proper motions of Milky Way dwarfs I: 3D Motions and Orbits
Hefan Li, Francois Hammer, Carine Babusiaux +5
Based on Gaia Early Data Release 3 (EDR3), we estimate the proper motions for 46 dwarf spheroidal galaxies (dSphs) of the Milky Way. The uncertainties in proper motions, determined…
The 5 Gyr evolution of sub-M* galaxies
Karen Disseau, Mathieu Puech, François Hammer +3
We gathered two complete samples of () galaxies, which are representative of the present-day galaxies and their counterparts at 5 Gyr a…
Young stars discovered in dwarf spheroidal galaxies confirm their recent infall into the Milky way
Francois Hammer, Piercarlo Bonifacio, Elisabetta Caffau +10
Recent observations from the ESA Gaia satellite and with the ESO VLT, have identified the presence of a population of young, 0.5 to 2 Gyr old, stars in the halo and in dwarf sphero…
Revisiting mass estimates of the Milky Way
Yongjun Jiao, Francois Hammer, Haifeng Wang +2
We use the rotation curve from Gaia data release (DR) 3 to estimate the mass of the Milky Way. We consider an Einasto density profile to model the dark matter component. We extrapo…
Age Estimations of M31 Globular Clusters from Their Spectral Energy Distributions
Jun Ma, Xu Zhou, David Burstein +4
This paper presents accurate spectral energy distributions (SEDs) of 16 M31 globular clusters (GCs) confirmed by spectroscopy and/or high spatial-resolution imaging, as well as 30…
Age and mass constraints for a young massive cluster in M31 based on spectral-energy-distribution fitting
Jun Ma, Song Wang, Zhenyu Wu +4
VDB0-B195D is a massive, blue star cluster in M31. It was observed as part of the Beijing-Arizona-Taiwan-Connecticut (BATC) Multicolor Sky Survey using 15 intermediate-band filters…
Orbital evidences for dark-matter-free Milky Way dwarf spheroidal galaxies
Francois Hammer, Yanbin Yang, Frederic Arenou +4
The nature of Milky Way dwarf spheroidals (MW dSphs) has been questioned, in particular whether they are dominated by dark matter (DM). Here we investigate an alternative scenario,…
Does the dwarf galaxy system of the Milky Way originate from Andromeda?
Sylvain Fouquet, François Hammer, Yanbin Yang +2
The Local Group is often seen to be a quiescent environment without significant merger events. However an ancient major merger may have occurred in the most massive galaxy. Numeric…
An Attempt to Search for Unintended Electromagnetic Radiation from Starlink Satellites with the 21 Centimeter Array: Methodology and RFI Characterization
Xupiao Yang, Qijun Zhi, Yanbin Yang +6
The rapid expansion of low-Earth-orbit (LEO) megaconstellations introduces new risks to radio astronomy from unintended electromagnetic radiation (UEMR). In this work, we present a…
The Accretion History of the Milky Way: III. Hydrodynamical Simulations of Galactic Dwarf Galaxies at First Infall
Jianling Wang, Francois Hammer, Yanbin Yang +3
Most Milky Way dwarf galaxies are much less bound to their host than are relics of Gaia-Sausage-Enceladus and Sgr. These dwarfs are expected to have fallen into the Galactic halo l…
The Progenitor of Supernova 2004dj in a Star Cluster
Xiaofeng Wang, Yanbin Yang, Tianmeng Zhang +5
The progenitor of type II-plateau supernova (SN) 2004dj is identified with a supergiant in a compact star cluster known as "Sandage Star 96" (S96) in the nearby spiral galaxy NGC 2…
Impact of merger histories on the timing argument estimate of the Local Group mass
Istiak Akib, François Hammer, Yanbin Yang
The timing argument (TA) aims to find the total mass of the Local Group (LG) from the relative motions of the Milky Way (MW) and Andromeda Galaxy (M31). However, the classical TA a…
037-B327 in M31: Luminous Globular Cluster or Core of a Former Dwarf Spheroidal Companion to M31?
Jun Ma, Sidney van den Bergh, Hong Wu +6
037-B327 is of interest because it is both the most luminous and the most highly reddened cluster known in M31. Deep observations with the Advanced Camera for Surveys on the Hubble…
EAGLE Spectroscopy of Resolved Stellar Populations Beyond the Local Group
Chris Evans, Yanbin Yang, Mathieu Puech +8
Valuable insights into galaxy evolution can be gleaned from studies of resolved stellar populations in the local Universe. Deep photometric surveys have provided tracers of the sta…
Evidence of ram pressure stripping of WLM, a dwarf galaxy far away from any large host galaxy
Yanbin Yang, Roger Ianjamasimanana, Francois Hammer +5
Dwarf galaxies are affected by all the evolutionary processes normally at work in galaxies of any mass. As fainter and less massive galaxies, however, dwarf galaxies are particular…
Age constraints for an M31 globular cluster from SEDs-fit
Jun Ma, Yanbin Yang, David Burstein +4
We have constrained the age of the globular cluster S312 in the Andromeda galaxy (M31) by comparing its multicolor photometry with theoretical stellar population synthesis models.…
An intriguing coincidence between the majority of vast polar structure dwarfs and a recent major merger at the M31 position
Istiak Akib, François Hammer, Yanbin Yang +2
A significant part of the Milky Way (MW) dwarf galaxies orbit within a Vast POlar Structure (VPOS), which is perpendicular to the Galactic disc and whose origin has not yet been id…
Galactic forces rule dynamics of Milky Way dwarf galaxies
Francois Hammer, Yanbin Yang, Frederic Arenou +4
Dwarf galaxies populating the Galactic halo are assumed to host the largest fractions of dark matter, as calculated from their velocity dispersions. Their major axes are preferenti…
Detection of the Keplerian decline in the Milky Way rotation curve
Yongjun Jiao, Francois Hammer, Haifeng Wang +4
Our position inside the Galactic disc had prevented us from establishing an accurate rotation curve, until the advent of Gaia, whose third data release (Gaia DR3) made it possible…
Time-average properties of major mergers: mergers significantly scatter high-z scaling relations
Mathieu Puech, Hector Flores, Myriam Rodrigues +2
Interpreting the scaling relations measured by recent large kinematic surveys of galaxies has remained hampered by large observational scatter. We show that the observed IS…
EAGLE Spectroscopy of Resolved Stellar Populations Beyond the Local Group
Chris Evans, Yanbin Yang, Mathieu Puech +8
We give an overview of the science case for spectroscopy of resolved stellar populations beyond the Local Group with the European Extremely Large Telescope (E-ELT). In particular,…
Stellar Population Properties and Evolution Analysis of NGC 628 with the Panchromatic Photometry
Hu Zou, Wei Zhang, Yanbin Yang +7
Panchromatic spectral energy distribution (SED) from the ultraviolet (UV), optical to infrared (IR) photometry of NGC 628, combined with the evolutionary stellar population synthes…
A possible impact near the Milky Way of a former major merger in the Local Group
Sylvain Fouquet, François Hammer, Yanbin Yang +2
The Milky Way (MW) dwarf system presents two exceptional features, namely it forms a thick plane called the Vast Polar Structure (VPOS), and the two biggest dwarves, the Magellanic…
Which Milky Way masses are consistent with the slightly declining 5-25 kpc rotation curve?
Yongjun Jiao, Francois Hammer, Jianling Wang +1
Discoveries of extended rotation curves have suggested the presence of dark matter in spiral galaxy haloes. It has led to many studies that estimated the galaxy total mass, mostly…
Toward a Complete Understanding of the Magellanic Stream Formation
Jianling Wang, Francois Hammer, Yanbin Yang +4
The Magellanic Clouds have lost most of their gas during their passage by the Milky Way, a property that has never been successfully modeled. Here we use accurate and mesh-free hyd…
The Formation of Large Galactic Disks Through The Hierarchical Scenario: Further consequences
Francois Hammer, Yanbin Yang, Hector Flores +1
Using the deepest and most complete observations of distant galaxies, we investigate the progenitors of present-day large spirals. Observations include spatially-resolved kinematic…