Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 2609.28030

The Neutral Hydrogen Gas Content of Star-forming and Quiescent S0 Galaxies

D. A. A. Lee·Karen L. Masters·David V. Stark·Z. Z. Abidin
View original source ↗Read source document ↗Export metadata ↓

Abstract

Lenticular (or S0) galaxies that remain actively star-forming (SFS0s) are a unique transition population among galaxies. We investigated the HI (21cm) neutral hydrogen content of a sample of lenticular galaxies identified from within the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey and which have been classified as star-forming or quiescent (qS0s). We compared these populations to each other and to a sample of star-forming spiral galaxies in MaNGA. We found that the HI Mass fraction and HI Deficiency of the SFS0s were intermediate between the quiescent S0s and the star-forming spirals, but most similar to the spirals. The HI depletion times of the quiescent S0's is very much longer than that of the SFS0 and spirals, which have roughly similar times. We also compared the molecular gas fractions of the three groups which shows that the lowest fraction of the three populations, followed by the star-forming S0s and then the star-forming spirals. A comparison of total baryonic mass comparisons indicates that the star-forming S0s have significantly lower masses than the qS0s in the sample. This suggests that the star-forming S0s must form from lower-mass progenitors (unobserved by MaNGA) which either accrete external gas, or loose spiral arms. The more massive quiescent S0s are a completely separate population, most likely to be formed either from fading star-forming spirals or from medium- to high-mass spirals undergoing mergers. The SFS0s in this sample cannot form from the quiescent S0s in this sample that receive in-falling gas, nor can they fade to create these qS0s.

Explore related subjects

astro-ph.GA

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

D. A. A. Lee, Karen L. Masters, David V. Stark, Z. Z. Abidin. 2026-09-23. The Neutral Hydrogen Gas Content of Star-forming and Quiescent S0 Galaxies. https://arxiv.org/abs/2609.28030

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Dark matter haloes from dwarf to massive galaxies: no systematic inner-density tension with ΛCDM hydrodynamical simulations

Two of the most prominent small-scale challenges to the cold dark matter (CDM) paradigm are the cusp-core and diversity-of-rotation-curves problems. The former concerns the shallow inner DM density profiles inferred for many galaxies compared with the cusps predicted by collisionless CDM, while the latter concerns the wider range of inner DM densities and rotation curve shapes inferred observationally than hydrodynamical simulations traditionally reproduce. Robust observational constraints on DM core sizes and halo densities are therefore essential for testing both the nature of DM and the impact of galaxy formation processes. We analyse the inner DM distribution of a curated sample of 48 gas-rich galaxies and 8 Milky Way gas-poor satellites, spanning 6 orders of magnitude in $M_\ast$. We find substantial scatter in DM core sizes and degrees of coreness, with both cuspy and cored haloes occurring over a broad $M_\ast$ range. The cores are energetically consistent with stellar feedback, requiring modest supernova energy coupling efficiencies of order $0.1-1\%$. Comparisons with the NIHAO, FIRE-2, and EDGE simulations reveal broad agreement in the inner DM densities and logarithmic slopes of observed and simulated galaxies. The main residual differences concern the steep slopes of some massive simulated galaxies and differences in SHMRs. Using a rotation-curve diversity diagnostic from previous work, we find that extreme discrepancies with simulations are absent from our curated sample and largely attributable to uncertain kinematics or baryonic mass distributions. Within the scope of our analysis, we find no evidence of a systematic inner-density tension between our galaxy sample and current $Λ$CDM hydrodynamical simulations. Together with the modest energetic requirements for core formation, this substantially alleviates the cusp-core and diversity-of-rotation-curves problems.

astro-ph.GA↗
arXiv2026

High-z galaxies with the JWST and the ELT: Toward Ever-finer Detail

The exploration of the early Universe is being transformed by the James Webb Space Telescope (JWST), which delivers unprecedented angular resolution at infrared wavelengths and opens a unique window redward of the K band (2um). Thanks to NIRCam, NIRISS, NIRSpec, and MIRI instruments, which provide both imaging and spectroscopy with exquisite efficiency, new classes of sources have emerged within the first years of operations. The first half-Gyr of cosmic time is now routinely probed, revealing massive blue/red galaxies and a population of Active Galactic Nuclei (AGN) appearing as "little red dots" together with a rest-frame near-infrared/optical view of sources across the reionization and post-reionization epochs. Angular resolution will remain pivotal in the 2030s - 2040s, when extreme adaptive optics (AO) facilities will be deployed on both (8 - 10)m (e.g., the VLT Multi-Conjugate-Adaptive-Optics (MCAO) - Assisted Visible Imager and Spectrograph, MAVIS) and on extremely large telescopes, like the 39m ELT (e.g., Multi-conjugate adaptive Optics Relay For ELT Observation, MORFEO). Operating at the diffraction limit, these facilities will improve JWST's resolution, with ELT achieving a factor of ~ 6 smaller Point-Spread-Function (PSF). An ELT diffraction-limited PSF (with a Full Width Half Maximum, FWHM ~ 8-12 mas) in the near infrared will resolve spatial scales <100 pc at any redshift (z ~< 18), revealing abundant star-forming clumps with sufficient sensitivity. Leveraging gravitational lensing as a cosmic telescope, even with moderate magnification factors (mu ~ 4-8), diffraction-limited 8m and 39m telescopes will probe physical scales ~< 25 pc, enabling systematic studies of star formation down to star-cluster scale at cosmological distances. Such observations are poised to become routine in the 2030s - 2040s.

astro-ph.GA↗
arXiv2026

Mass-Dependent Dark Matter Deficit from Inelastic Scattering

Recent stellar-kinematic and neutral-hydrogen observations indicate a dark matter deficit within the central tens of kiloparsecs of nearby galaxies that grows systematically with stellar mass relative to hydrodynamical simulations. We show that this mass dependence can arise from exothermic inelastic dark matter with strongly velocity-dependent scattering. Two nearly degenerate dark matter states interact through vector and scalar mediators with opposite-sign contributions and unequal ranges. The resulting coupled-channel dynamics suppresses $s$-wave conversion at low velocity while retaining a $p$-wave enhancement at several hundred $\rm km/s$, where down-scattering injects kinetic energy and lowers central dark matter densities. At dwarf velocities, conversion remains suppressed while elastic scattering can still drive core formation consistent with the observed dwarf-clustering pattern. A late dark-sector phase transition, along with the low-velocity suppression, preserves a large excited-state fraction until halo formation. Using representative halos spanning the four observed stellar-mass bins, we find that the model accounts for the inferred dark matter deficit in all four bins, including its systematic growth with stellar mass, while its impact weakens toward cluster velocities. The growing discrepancy with hydrodynamical simulations may therefore offer a glimpse of previously hidden dark matter microphysics.

astro-ph.GA↗