Composite Bulges. III. A Study of Nuclear Star Clusters in Nearby Spiral Galaxies

Ashok, Aishwarya; Seth, Anil; Erwin, Peter; Debattista, Victor P.; de Lorenzo-Cáceres, Adriana; Gadotti, Dmitri A.; Méndez-Abreu, Jairo; Beckman, John E.; Bender, Ralf; Drory, Niv; Fisher, Deanne; Hopp, Ulrich; Kluge, Matthias; Kolcu, Tutku; Maciejewski, Witold; Mehrgan, Kianusch; Parikh, Taniya; Saglia, Roberto; Seidel, Marja; Thomas, Jens
Bibliographical reference

The Astrophysical Journal

Advertised on:
11
2023
Number of authors
20
IAC number of authors
3
Citations
1
Refereed citations
0
Description
We present photometric and morphological analyses of nuclear star clusters (NSCs)-very dense, massive star clusters present in the central regions of most galaxies-in a sample of 33 massive disk galaxies within 20 Mpc, part of the "Composite Bulges Survey." We use data from the Hubble Space Telescope including optical (F475W and F814W) and near-IR (F160W) images from the Wide Field Camera 3. We fit the images in 2D to take into account the full complexity of the inner regions of these galaxies (including the contributions of nuclear disks and bars), isolating the NSC and bulge components. We derive NSC radii and magnitudes in all three bands, which we then use to estimate NSC masses. Our sample significantly expands the sample of massive late-type galaxies with measured NSC properties. We clearly identify NSCs in nearly 80% of our galaxies, putting a lower limit on the nucleation fraction in these galaxies that is higher than previous estimates. We find that the NSCs in our massive disk galaxies are consistent with previous NSC mass-NSC radius and galaxy mass-NSC mass relations. However, we also find a large spread in NSC masses, with a handful of galaxies hosting very low-mass, compact clusters. Our NSCs are aligned in PA with their host galaxy disks but are less flattened. They show no correlations with bar or bulge properties. Finally, we find the ratio of NSC to BH mass in our massive disk galaxy sample spans a factor of ~300.
Related projects
Group members
Traces of Galaxy Formation: Stellar populations, Dynamics and Morphology

We are a large, diverse, and very active research group aiming to provide a comprehensive picture for the formation of galaxies in the Universe. Rooted in detailed stellar population analysis, we are constantly exploring and developing new tools and ideas to understand how galaxies came to be what we now observe.

Ignacio
Martín Navarro
Project Image
Spiral Galaxies: Evolution and Consequences

Our small group is well known and respected internationally for our innovative and important work on various aspects of the structure and evolution of nearby spiral galaxies. We primarily use observations at various wavelengths, exploiting synergies that allow us to answer the most pertinent questions relating to what the main properties of

Johan Hendrik
Knapen Koelstra
Supermassive black holes modify the distribution of molecular gas in the central regions of galaxies. Credit: HST and C. Ramos Almeida.
Nuclear Activity in Galaxies: a 3D Perspective from the Nucleus to the Outskirts

This project consists of two main research lines. First, the study of quasar-driven outflows in luminous and nearby obscured active galactic nuclei (AGN) and the impact that they have on their massive host galaxies (AGN feedback). To do so, we have obtained Gran Telescopio CANARIAS (GTC) infrared and optical observations with the instruments

Cristina
Ramos Almeida