Related papers: Evidence for Ultra-Diffuse Galaxy Formation Throug…
Tidal interactions between galaxies often give rise to tidal tails, which can harbor concentrations of stars and interstellar gas resembling dwarf galaxies. Some of these tidal dwarf galaxies (TDGs) have the potential to detach from their…
It has been shown that ultra-diffuse galaxies (UDGs) have higher specific frequencies of globular clusters on average than other dwarf galaxies with similar luminosities. The UDG NGC5846-UDG1 is among the most extreme examples of globular…
We present new observations of the late-stage merger galaxy NGC 7727, including HST/WFPC2 images and long-slit spectra obtained with the Clay telescope. NGC 7727 is relatively luminous ($M_V = -21.7$) and features two unequal tidal tails,…
We present deep optical imaging and photometry of four objects classified as "Almost-Dark" galaxies in the ALFALFA survey because of their gas-rich nature and extremely faint or missing optical emission in existing catalogs. They have HI…
This paper presents a detailed analysis of a gas-rich star-forming ultra-diffuse galaxy (UDG) as part of the ESO Large Programme 'Looking into the faintEst WIth MUSE (LEWIS)'. Among the UDGs in the LEWIS sample, UDG 6 is the only galaxy…
[Abridged...] We investigate the process of galaxy formation as can be observed in the only currently forming galaxies -- the so-called Tidal Dwarf Galaxies, hereafter TDGs -- through observations of the molecular gas detected via its CO…
We report on the results of radio observations in the 21 cm emission line of atomic hydrogen (HI) of four relatively isolated ultra-diffuse galaxies (UDGs): DGSAT I, R-127-1, M-161-1, and SECCO-dI-2. Our Effelsberg observations resulted in…
One possible channel for the formation of dwarf galaxies involves birth in the tidal tails of interacting galaxies. We report the detection of a bright UV tidal tail and several young tidal dwarf galaxy candidates in the post-merger galaxy…
With the published data of apparent axis ratios for 1109 ultra-diffuse galaxies (UDGs) located in 17 low-redshift (z~ 0.020 - 0.063) galaxy clusters and 84 UDGs in 2 intermediate-redshift (z~ 0.308 - 0.348) clusters, we take advantage of a…
In dwarf galaxies, nuclear star clusters (NSCs) are believed to primarily form from the migration and merger of globular clusters (GCs), with a possible contribution from in-situ star-forming activity triggered by gas infall. We present the…
Tidal ring galaxies are observed rarely in the local universe due to their intrinsically transient nature. The tidal ring structures are the result of strong interactions between gas-rich stellar disks and smaller galactic systems and do…
Due to the peculiar properties of ultra-diffuse galaxies (UDGs), understanding their origin presents a major challenge. Previous X-ray studies demonstrated that the bulk of UDGs lack substantial X-ray emission, implying that they reside in…
Tidal Dwarf Galaxies (TDGs) are objects presently forming from gas which has been expelled from their parent galaxies during an interaction. We observed the CO emission of a sample of 11 TDGs, of which 8 were detected. The CO is found at…
We present results from a survey of dwarf galaxy candidates in the vicinity of strongly interacting galaxies. The goal of the survey was a test of the hypothesis that massive condensations of stars and HI in tidal tails of large interacting…
We present a study of ultra-diffuse galaxies (UDGs) in the Virgo Cluster based on deep imaging from the Next Generation Virgo Cluster Survey (NGVS). Applying a new definition for the UDG class based on galaxy scaling relations, we define…
Galactic collisions trigger a number of phenomena, such as transportation inward of gas from distances of up to kiloparsecs from the center of a galaxy to the nuclear region, fuelling a central starburst or nuclear activity. The inverse…
High speed collisions, although current in clusters of galaxies, have long been neglected, as they are believed to cause little damages to galaxies, except when they are repeated, a process called harassment. In fact, they are able to…
We present the detection of a large population of ultra diffuse galaxies (UDGs) in two massive galaxy clusters, Abell S1063 at $z=0.348$ and Abell 2744 at $z=0.308$, based on F814W and F105W images in the Hubble Frontier Fields Program. We…
The evolution of galaxies depends on their interaction with the surrounding environment. Ultra-diffuse galaxies (UDGs) have been found in large numbers in clusters. We detected a few star-forming blobs in the VESTIGE survey, located at…
Ultra-diffuse galaxies (UDGs) are unusual galaxies with low luminosities, similar to classical dwarf galaxies, but sizes up to $\sim\!5$ larger than expected for their mass. Some UDGs have large populations of globular clusters (GCs),…