Bibliographic Details
| Title: |
Deep Photometric Observations of Ultra-Faint Milky Way Satellites Centaurus I and Eridanus IV |
| Authors: |
Casey, Quinn O., Mutlu-Pakdil, Burçin, Sand, David J., Pace, Andrew B., Crnojevic, Denija, Doliva-Dolinsky, Amandine, Cerny, William, Heiger, Mairead E., Riley, Alex H., Ji, Alexander P., Limberg, Guilherme, Marin, Laurella, Martínez-Vázquez, Clara E., Medina, Gustavo E., Li, Ting S., Campana, Sasha N., Chaturvedi, Astha, Sakowska, Joanna D., Zenteno, Alfredo, Carballo-Bello, Julio A., Navabi, Mahdieh, Bom, Clecio R. |
| Publication Year: |
2025 |
| Collection: |
Astrophysics |
| Subject Terms: |
Astrophysics - Astrophysics of Galaxies |
| More Details: |
We present deep Magellan$+$Megacam imaging of Centaurus I (Cen I) and Eridanus IV (Eri IV), two recently discovered Milky Way ultra-faint satellites. Our data reach $\sim2-3$ magnitudes deeper than the discovery data from the DECam Local Volume Exploration (DELVE) Survey. We use these data to constrain their distances, structural properties (e.g., half-light radii, ellipticity, and position angle), and luminosities. We investigate whether these systems show signs of tidal disturbance, and identify new potential member stars using Gaia EDR3. Our deep color-magnitude diagrams show that Cen I and Eri IV are consistent with an old ($\tau\sim 13.0$ Gyr) and metal-poor ($\text{[Fe/H]}\le-2.2$) stellar population. We find Cen I to have a half-light radius of $r_{h}=2.60\pm0.30'$ ($90.6\pm11$ pc), an ellipticity of $\epsilon=0.36\pm0.05$, a distance of $D=119.8\pm4.1$ kpc ($m-M=20.39\pm0.08$ mag), and an absolute magnitude of $M_{V}=-5.39\pm0.19$. Similarly, Eri IV has $r_{h}=3.24\pm0.48'$ ($65.9\pm10$ pc), $\epsilon=0.26\pm0.09$, $D=69.9\pm3.6$ kpc ($m-M=19.22\pm0.11$ mag), and $M_{V}=-3.55\pm0.24$. These systems occupy a space on the size-luminosity plane consistent with other known Milky Way dwarf galaxies which supports the findings from our previous spectroscopic follow-up. Cen I has a well-defined morphology which lacks any clear evidence of tidal disruption, whereas Eri IV hosts a significant extended feature with multiple possible interpretations.
Comment: 14 pages, 3 figures. Accepted for publication in ApJ |
| Document Type: |
Working Paper |
| Access URL: |
http://arxiv.org/abs/2501.04772 |
| Accession Number: |
edsarx.2501.04772 |
| Database: |
arXiv |
