Although ultra diffuse galaxies (UDGs) are found in large numbers in clusters of galaxies, the role of the cluster environment in shaping their low surface brightness and large sizes is still uncertain. Here, we examine a sample of UDGs in the Hydra I cluster (D = 51 Mpc) with new radial velocities obtained as part of the LEWIS (Looking into the

The different structures we observe in the Universe result from cosmic evolution starting from primordial seeds. These are believed to have originated from quantum fluctuations. During the inflationary epoch, they were stretched and frozen just after the Big Bang, giving rise to an almost homogeneous, closely Gaussian-distributed Universe. However

Galaxies in the Universe are distributed in a web-like structure characterized by different large-scale environments: dense clusters, elongated filaments, sheetlike walls and under-dense regions, called voids 1-5. The low density in voids is expected to affect the properties of their galaxies. Indeed, previous studies 6-14 have shown that galaxies

The kinematic and thermal Sunyaev-Zel'dovich (kSZ and tSZ) effects probe the abundance and thermodynamics of ionized gas in galaxies and clusters. We present a new hybrid estimator to measure the kSZ effect by combining cosmic microwave background temperature anisotropy maps with photometric and spectroscopic optical survey data. The method

M31N 2008-12a, located in the Andromeda galaxy (M31), is the best studied recurrent nova. It presents periodic outbursts with about one year between eruptions. However, the annual eruption date varies from year to year. In order to discover the annual eruption and facilitate the multi-wavelength follow-up, a monitoring campaign with nightly cadence

We report the discovery and Doppler mass measurement of a 7.4 days 2.3 R ⊕ mini-Neptune around a metal-poor K dwarf BD+29 2654 (TOI-2018). Based on a high-resolution Keck/HIRES spectrum, the Gaia parallax, and multiwavelength photometry from the UV to the mid-infrared, we found that the host star has ${T}_{\mathrm{eff}}={4174}_{-42}^{+34}$ K, $