galaxies

Galaxy And Mass Assembly (GAMA): The Dependence of Star Formation on Surface Brightness in Low Redshift Galaxies

First author: S. Phillipps The star formation rate in galaxies is well known to correlate with stellar mass (the `star-forming main sequence’). Here we extend this further to explore any additional dependence on galaxy surface brightness, a proxy for stellar mass surface density. We use a large sample of low redshift ($z \leq 0.08$) galaxies from the GAMA survey which have both SED derived star formation rates and photometric bulge-disc decompositions, the latter providing measures of disc surface brightness and disc masses.

Lopsided Galaxies in a cosmological context: a new galaxy-halo connection

First author: Silvio Varela-Lavin Disc galaxies commonly show asymmetric features in their morphology, such as warps and lopsidedness. These features can provide key information regarding the recent evolution of a given disc galaxy. In the nearby Universe, up to ~30 percent of late-type galaxies display a global non-axisymmetric lopsided mass distribution, but little attention has been paid to the origin of this perturbation. In this work, we study the origin of lopsided perturbations in simulated disc galaxies extracted from the TNG50 simulation of the IllustrisTNG project.

Merger Signatures are Common, but not Universal, In Massive, Recently-Quenched Galaxies at z~0.7

First author: Margaret Verrico We present visual classifications of merger-induced tidal disturbances in 143 $\rm{M}* \sim 10^{11}\rm{M}\odot$ post-starburst galaxies at z$\sim$0.7 identified in the SQuIGG$\vec{L}$E Sample. This sample spectroscopically selects galaxies from the Sloan Digital Sky Survey that have stopped their primary epoch of star formation within the past $\sim$500 Myrs. Visual classifications are performed on Hyper Suprime Cam (HSC) i-band imaging. We compare to a control sample of mass- and redshift-matched star-forming and quiescent galaxies from the Large Early Galaxy Census and find that post-starburst galaxies are more likely to be classified as disturbed than either category.

On the sociology and hierarchy of voids: a study of seven CAVITY nearby galaxy voids and their dynamical CosmicFlows-3 environment

First author: H. M. Courtois Context. The present study addresses a key question for our understanding of the relation between void galaxies and their environment: the relationship between luminous and dark matter in and around voids. Aims. To explore how empty of matter local Universe voids are, we study the full (dark+luminous) matter content of seven nearby cosmic voids that are fully contained within the CosmicFlows-3 volume. Methods. The cosmic voids matter density profiles are independently obtained using two different methods.

Orientations of DM Halos in FIRE-2 Milky Way-mass Galaxies

First author: Jay Baptista The shape and orientation of dark matter (DM) halos are sensitive to the micro-physics of the DM particle, yet in many mass models, the symmetry axes of the Milky Way’s DM halo are often assumed to be aligned with the symmetry axes of the stellar disk. This is well-motivated for the inner DM halo but not for the outer halo. We use zoomed cosmological-baryonic simulations from the Latte suite of FIRE-2 Milky Way-mass galaxies to explore the evolution of the DM halo’s orientation with radius and time, with or without a major merger with a Large Magellanic Cloud (LMC) analog, and when varying the DM model.

Reconstructing the extended structure of multiple sources strongly lensed by the ultra-massive elliptical galaxy SDSS J0100+1818

First author: A. Bolamperti We study the total and baryonic mass distributions of the deflector SDSS J0100+1818 through a full strong lensing analysis. The system is composed by an ultra-massive early-type galaxy at $z=0.581$, with total stellar mass of $(1.5 \pm 0.3) 10^{12}$ M$\odot$ and stellar velocity dispersion of ($450 \pm 40$) km s$^{-1}$, surrounded by ten multiple images of three background sources, two of which spectroscopically confirmed at $z=1.

The Dark Energy Survey Year 3 high redshift sample: Selection, characterization and analysis of galaxy clustering

First author: C. Sánchez The fiducial cosmological analyses of imaging galaxy surveys like the Dark Energy Survey (DES) typically probe the Universe at redshifts $z < 1$. This is mainly because of the limited depth of these surveys, and also because such analyses rely heavily on galaxy lensing, which is more efficient at low redshifts. In this work we present the selection and characterization of high-redshift galaxy samples using DES Year 3 data, and the analysis of their galaxy clustering measurements.

The volumetric star formation law in nearby galaxies

First author: C. Bacchini Star formation laws are empirical relations between the cold gas (HI+H$_2$) content of a galaxy and its star formation rate (SFR), being crucial for any model of galaxy formation and evolution. A well known example of such laws is the Schmidt-Kennicutt law, which is based on the projected surface densities. However, it has been long unclear whether a more fundamental relation exists between the intrinsic volume densities.

Toward Accurate Modeling of Galaxy Clustering on Small Scales: Halo Model Extensions & Lingering Tension

First author: Gillian D. Beltz-Mohrmann This paper represents an effort to provide robust constraints on cosmology and the galaxy-halo connection using a fully numerical model of small-scale galaxy clustering. We explore two extensions to the standard Halo Occupation Distribution model: assembly bias, whereby halo occupation depends on both halo mass and the larger environment, and velocity bias, whereby galaxy velocities do not perfectly trace the velocity of the dark matter within the halo.

VERTICO III: The Kennicutt-Schmidt relation in Virgo cluster galaxies

First author: M. J. Jiménez-Donaire In this VERTICO science paper we aim to study how the star formation process depends on galactic environment and gravitational interactions in the context of galaxy evolution. We explore the scaling relation between the star formation rate (SFR) surface density and the molecular gas surface density, also known as the Kennicutt-Schmidt (KS) relation, in a subsample of Virgo cluster spiral galaxies. We use new ACA and TP observations from the VERTICO-ALMA Large Program at 720pc resolution to resolve the molecular gas content, as traced by the 12CO(2-1) transition, across the disks of 37 spiral galaxies in the Virgo cluster.