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Freeze-in production of sterile neutrino dark matter in a gauged U(1)‧ model with inverse seesaw
Poddar, Tanmay Kumar; Das, Arindam; Goswami, Srubabati +1 more
We consider a general, anomaly free U(1)‧ extension of the Standard Model (SM) where the neutrino mass is generated at the tree level via the inverse seesaw mechanism. The model contains three right handed neutrinos, three additional singlet fermions, one extra complex scalar and a neutral gauge boson (Z‧). Instead of resorting to a specific U(1) …
Proper Motions and Orbits of Distant Local Group Dwarf Galaxies from a Combination of Gaia and Hubble Data
van der Marel, Roeland P.; Watkins, Laura L.; Sacchi, Elena +12 more
We have determined the proper motions (PMs) of 12 dwarf galaxies in the Local Group (LG), ranging from the outer Milky Way (MW) halo to the edge of the LG. We used the Hubble Space Telescope (HST) as the first and Gaia as the second epoch using the GaiaHub software. For Leo A and Sag DIG, we also used multi-epoch HST measurements relative to backg…
A Rest-frame Near-IR Study of Clumps in Galaxies at 1 < z < 2 Using JWST/NIRCam: Connection to Galaxy Bulges
Ho, Luis C.; Daddi, Emanuele; Bottrell, Connor +4 more
A key question in galaxy evolution has been the importance of the apparent "clumpiness" of high-redshift galaxies. Until now, this property has been primarily investigated in rest-frame UV, limiting our understanding of their relevance. Are they short-lived or are they associated with more long-lived massive structures that are part of the underly…
Ubiquitous radio emission in quasars: Predominant AGN origin and a connection to jets, dust, and winds
Prandoni, I.; Alexander, D. M.; Hardcastle, M. J. +16 more
We present a comprehensive study of the physical origin of radio emission in optical quasars at redshifts z < 2.5. We focus particularly on the associations between compact radio emission, dust reddening, and outflows identified in our earlier work. Leveraging the deepest low-frequency radio data available to date (LoTSS Deep DR1), we achieve r…
JWST Reveals a Luminous Infrared Source at the Position of the Failed Supernova Candidate N6946-BH1
Smith, Nathan; Sand, David J.; Jencson, Jacob E. +4 more
N6946-BH1 (BH1) is the first plausible candidate for a failed supernova (SN), a peculiar event in which a massive star disappears without the expected bright SN, accompanied by collapse into a black hole (BH). Following a luminous outburst in 2009, the source experienced a significant decline in optical brightness, while maintaining a persistent I…
The black hole low-mass X-ray binary V404 Cygni is part of a wide triple
Vanderburg, Andrew; Chakrabarty, Deepto; El-Badry, Kareem +7 more
Evidence suggests that, when compact objects such as black holes and neutron stars form, they may receive a 'natal kick', during which the stellar remnant gains momentum. Observational evidence for neutron star kicks is substantial1,2, yet is limited for black hole natal kicks, and some proposed black hole formation scenarios result in …
Balmer Decrement Anomalies in Galaxies at z ∼ 6 Found by JWST Observations: Density-bounded Nebulae or Excited H I Clouds?
Ono, Yoshiaki; Ouchi, Masami; Nakagawa, Takao +11 more
We investigate the physical origins of the Balmer decrement anomalies in GS-NDG-9422 and RXCJ2248-ID galaxies at z ∼ 6 whose Hα/Hβ values are significantly smaller than 2.7, the latter of which also shows anomalous Hγ/Hβ and Hδ/Hβ values beyond the errors. Because the anomalous Balmer decrements are not reproduced under the Case B recombination, w…
A portrait of the vast polar structure as a young phenomenon: Hints from its member satellites
Steinmetz, M.; Taibi, S.; Khoperskov, S. +2 more
Context. It has been observed that several Milky Way (MW) satellite dwarf galaxies are distributed along a coherent planar distribution known as the vast polar structure (VPOS).
Aims: Here we investigate whether MW satellites located on the VPOS have different physical and orbital properties from those not associated with it.
Methods: Us…
A dusty streamer infalling onto the disk of a class I protostar. ALMA dual-band constraints on grain properties and the mass-infall rate
Testi, L.; Klessen, R. S.; Manara, C. F. +15 more
Context. Observations of interstellar material infalling onto star- and planet-forming systems have become increasingly common thanks to recent advancements in radio interferometry. These structures have the potential to alter the dynamics of protoplanetary disks significantly by triggering the formation of substructures, inducing shocks, and modi…
Cosmic Vine: A z = 3.44 large-scale structure hosting massive quiescent galaxies
Brammer, Gabriel; Greve, Thomas R.; Gillman, Steven +15 more
We report the discovery of a large-scale structure at z = 3.44 revealed by JWST data in the Extended Groth Strip (EGS) field. This structure, called the Cosmic Vine, consists of 20 galaxies with spectroscopic redshifts at 3.43 < z < 3.45 and six galaxy overdensities (4 − 7σ) with consistent photometric redshifts, making up a vine-like struct…