相关论文: Ultra-Compact Dwarf Candidates Near the Lensing Ga…

Observational studies of ultra-diffuse galaxies (UDGs) represent a significant challenge because of their very low surface brightnesses. A feasible approach is to identify "future" UDGs when their stars are still young. Using data mining,…

We present a gravitational lensing study of the massive galaxy cluster A2219 (redshift 0.22). This investigation is based on multicolour images from U through H, which allows photometric redshifts to be estimated for the background sources.…

Extended stellar clusters with effective radii larger than 10 pc have been found in various environments. Objects with masses comparable to globular clusters (GCs) are called extended clusters (ECs), while objects with masses in the dwarf…

We report Keck LRIS observations of an arc-like background galaxy near the center of Abell 2152 (z=0.043), one of the three clusters comprising the Hercules supercluster. The background object has a redshift z=0.1423 and is situated 25…

Time-delay cosmography (TDC) using multiply-lensed quasars (QSOs) by galaxies has recently emerged as an independent and competitive tool to measure the value of the Hubble constant. Lens galaxy clusters hosting multiply-imaged QSOs, when…

We present HST/ACS $g$ and $z$ photometry and half-light radii $R_{\rm h}$ measurements of 360 globular cluster (GC) candidates around the nearby S0 galaxy NGC 3115. We also include Subaru/Suprime-Cam $g$, $r$, and $i$ photometry of 421…

We present new imaging and spectroscopic observations of six ultra-compact dwarf (UCD) galaxies in the Virgo Cluster, along with re-analysed data for five Fornax Cluster UCDs. These are the most luminous UCDs: -14<Mv<-12 mag. Our HST…

We present the initial results of a Hubble Space Telescope/ACS snapshot survey of 16 nearby, edge-on, late-type galaxies covering a range in distance from 2 to 19 Mpc. The images of these galaxies show significant resolved stellar…

We report the discovery of ultra-diffuse galaxies (UDGs) in Abell 370 ($z=0.375$). We find 46 UDGs in Abell 370 from the images of the Hubble Frontier Fields (HFF). Most UDGs are low-luminosity red sequence galaxies, while a few of them are…

Ultra Diffuse Galaxies (UDGs), a type of large Low Surface Brightness (LSB) galaxies with particularly large effective radii (r_eff > 1.5 kpc), are now routinely studied in the local (z<0.1) universe. While they are found to be abundant in…

Ultra diffuse galaxies, characterized by their low surface brightness and large physical size, constitute a subclass of dwarf galaxies that challenge our current understanding of galaxy formation and evolution. In this paper, we probe the…

We present a weak lensing analysis of one of the most distant massive galaxy cluster known, RDCS 1252.9-2927 at z=1.24, using deep images from the Advanced Camera for Survey (ACS) on board the Hubble Space Telescope (HST). By taking…

We present 226 large ultra-diffuse galaxy (UDG) candidates ($r_e > 5.3$\arcsec, $\mu_{0,g} > 24$ mag arcsec$^{-2}$) in the SDSS Stripe 82 region recovered using our improved procedure developed in anticipation of processing the entire…

A spectroscopic follow up of Ultra-Compact Dwarf (UCD) candidates in the fossil group NGC 1132 is undertaken with the Gemini Multi Object Spectrograph (GMOS). These new Gemini spectra prove the presence of six UCDs in the fossil group NGC…

We present a study of bar and host disk evolution in a dense cluster environment, based on a sample of ~800 bright (MV <= -18) galaxies in the Abell 901/2 supercluster at z~0.165. We use HST ACS F606W imaging from the STAGES survey, and…

We present a deep UBI CCD survey using the Palomar 5-m telescope of a sample of high X-ray luminosity, distant clusters selected from the ROSAT All-Sky Survey. The 10 clusters lie at z=0.22-0.28, an era where evolutionary effects have been…

We present HST WFPC2 imaging of the nearby low-surface-brightness dwarf spheroidal galaxy ESO 410-G005, which has been resolved into stars for the first time. The resulting color-magnitude diagram for about 2500 stars shows a red giant…

We present the results of a search for high-redshift ($z>9$) galaxy candidates in the JWST UNCOVER survey, using deep NIRCam and NIRISS imaging in 7 bands over $\sim45$ arcmin$^2$ and ancillary HST observations. The NIRCam observations…

~Deep photometric data in the V-, R-, I-, z- and K-bands for the cluster of galaxies EIS 0048-2942 are used to investigate the properties of the galaxy populations at z~0.64 in a field of 2.5x2.5 Mpc^2. The sample of candidate cluster…

We present results from a near/mid IR search for submillimetre galaxies over a region of 6230 sq deg. of the southern sky. We used a cross-correlation of the VISTA Hemispheric Survey (VHS) and the WISE database to identify bright galaxies…