- The paper reveals the discovery of a 510 kpc-long, ultra-faint stellar stream formed by tidal disruption in the Coma Cluster.
- It employs deep g and r band imaging from the Jeanne Rich and William Herschel Telescopes alongside Illustris-TNG50 simulations to validate its formation scenario.
- The findings underscore the stream's potential to probe dark matter distributions and enhance our understanding of galaxy evolution.
A Giant Thin Stellar Stream in the Coma Galaxy Cluster
The paper entitled "A Giant Thin Stellar Stream in the Coma Galaxy Cluster" by Román et al. presents a detailed paper of an extraordinary astrophysical object, the Giant Coma Stream (GCS). This stellar stream, embedded within the Coma Galaxy Cluster, exhibits unique characteristics that extend our understanding of the role of such structures in galaxy formation and evolution.
Detection and Morphology
The GCS was detected through deep observations in the g and r bands utilizing the Jeanne Rich Telescope (JRT) and confirmed with follow-up observations using the William Herschel Telescope (WHT). It is characterized by an astonishingly weak surface brightness of approximately 29.5 mag arcsec-2 in the g-band, structuring a coherent and elongated feature spanning 510 kpc in length—a scale that far surpasses typical known stellar streams.
No identifiable core or remnant galaxy was detected in association with GCS, indicating its status as a free-floating structure in the cluster’s periphery, located roughly 0.8 Mpc from the cluster’s center. The absence of a background galaxy, combined with its linear shape and thin profile, suggests an origin through tidal disruption.
Simulation and Theoretical Modeling
By employing the Illustris-TNG50 simulation, the paper identifies a comparable stream, formed from the tidal disruption of a low-mass passive dwarf galaxy in a cosmological context. The simulation highlights the rarity of such streams on cluster scales but confirms their predicted occurrence in the Λ-CDM model when specific conditions of progenitor properties and environmental interaction are met.
Implications and Future Perspectives
The discovery of the GCS highlights the capability of clusters to host stellar streams, thus expanding the potential realms for probing the dark matter distribution and its substructures across different cosmic environments. The exploration of these ultra-low surface brightness features may yield significant insights into the gravitational potentials shaping large-scale structures, contributing immensely to near-field cosmology.
Observationally, the GCS sets a precedent for the detection of such faint and extended features, inspiring future optical surveys with upcoming facilities, such as the Rubin Observatory and Euclid, which are expected to dramatically improve the detection threshold and perhaps uncover more such structures.
Summary
The findings of Román et al. pose intriguing questions about the detectability and prevalence of similar structures in dense environments like galaxy clusters and stress the need for advanced simulations coupled with observatory capabilities sensitive to low-surface-brightness phenomena. As research into this field continues, the GCS serves as an archetype for studying the complex interplay of gravitational interactions in shaping galaxy structures.