Probing Asymmetric Structures in the Outskirts of Galaxies

Wen, ZhangZheng; Zheng, Xianzhong; An, Fangxia

doi:10.1088/0004-637x/787/2/130

Cited by 20 publications

(31 citation statements)

References 68 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We measure morphological parameters A O and D O from HST images and visually examine the selected merging galaxies for apparent tidal tails. The parent sample is divided into four mass bins and four redshift bins to address the relationships of the merger rate with stellar mass and redshift (e.g., Lin et al 2004;Bundy et al 2005;de Ravel et al 2009;B10 Wen et al (2014) give quantitative measures of galaxy structures in the outskirts. The outskirts of a galaxy refers to the outer halflight region (OHR) divided by an elliptical aperture from the inner half-light region (IHR) of the galaxy.…”

Section: Sample Selectionmentioning

confidence: 99%

“…Such disturbed features can be caught in visual inspection (e.g., Jogee et al 2009;Bridge et al 2010, hereafter B10). The non-parametric measurements are to quantify morphological parameters, including the rotational asymmetry A (Conselice 2003), (Lotz et al 2004) or A O −D O (Wen et al 2014), and separate mergers from those with regular morphologies in the corresponding parametric space. However, morphology studies largely depend on the quality of imaging data as cosmic dimming effect may cause redshiftdependent biases.…”

Section: Introductionmentioning

confidence: 99%

“…The morphological parameters rotational asymmetry A, Gini and M 20 are likely insensitive to probe of such faint structures in a galaxy because these parameters are flux weighted and usually dominated by luminous structures of the galaxy. Wen et al (2014) developed a novel A O − D O method to select disturbed morphologies through quantifying the outer asymmetry (A O ) and the deviation of the intensity weighted centroids of the outer half light region and the inner half light region (D O ) of a galaxy. This technique is efficient in detecting tidal-tailed galaxies (see Wen et al 2014 for more details).…”

Section: Introductionmentioning

confidence: 99%

“…Wen et al (2014) developed a novel A O − D O method to select disturbed morphologies through quantifying the outer asymmetry (A O ) and the deviation of the intensity weighted centroids of the outer half light region and the inner half light region (D O ) of a galaxy. This technique is efficient in detecting tidal-tailed galaxies (see Wen et al 2014 for more details). Galaxies of different morphological types fall on a tight sequence in the A O versus D O diagram and the tailed galaxies usually have larger A O and D O relative to those with regular morphologies.…”

Section: Introductionmentioning

confidence: 99%

“…The segmentation maps will be used to perform morphological analysis. We set the detection threshold to be 0.8 σ of background noise level in order to detect extended faint tidal structures (see Wen et al 2014 for more details).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

MERGING GALAXIES WITH TIDAL TAILS IN COSMOS TO z = 1

Wen¹,

Zheng²

2016

ApJ

View full text Add to dashboard Cite

Tidal tails are created in major mergers involving disk galaxies. How the tidal tails trace the assembly history of massive galaxies remains to be explored. We identify a sample of 461 merging galaxies with long tidal tails from 35 076 galaxies mass-complete at M ≥ 10 9.5 M and 0.2 ≤ z ≤ 1 based on HST/ACS F814W imaging data and public catalogs of the COSMOS field. The long tails refer to these with length equal to or longer than the diameter of their host galaxies. The mergers with tidal tails are selected using our novel A O − D O technique for strong asymmetric features together with visual examination. Our results show that the fraction of tidaltailed mergers evolves mildly with redshift, as ∼ (1 + z) 2.0±0.4 , and becomes relatively higher in less massive galaxies out to z = 1. With a timescale of 0.5 Gyr for the tidal-tailed mergers, we obtain that the occurrence rate of such mergers follows 0.01 ± 0.007 (1 + z) 2.3±1.4 Gyr −1 and corresponds to ∼ 0.3 events since z = 1 and roughly one-third of the total budget of major mergers from the literature. For disk-involved major mergers, nearly half of them have undergone a phase with long tidal tails.

show abstract

Section: Sample Selectionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

MERGING GALAXIES WITH TIDAL TAILS IN COSMOS TO z = 1

Wen¹,

Zheng²

2016

ApJ

View full text Add to dashboard Cite

show abstract

Fine-grained photometric classification using multi-model fusion method with redshift estimation

Cheng,

Liu,

Zeraatgri

et al. 2024

Journal of High Energy Astrophysics

View full text Add to dashboard Cite

Characterization of low surface brightness structures in annotated deep images

Sola

Duc

Richards

et al. 2022

A&A

View full text Add to dashboard Cite

Context. The identification and characterization of low surface brightness (LSB) stellar structures around galaxies such as tidal debris of ongoing or past collisions is essential to constrain models of galactic evolution. So far most efforts have focused on the numerical census of samples of varying sizes, either through visual inspection or more recently with deep learning. Detailed analyses including photometry have been carried out for a small number of objects, essentially because of the lack of convenient tools able to precisely characterize tidal structures around large samples of galaxies. Aims. Our goal is to characterize in detail, and in particular obtain quantitative measurements, of LSB structures identified in deep images of samples consisting of hundreds of galaxies. Methods. We developed an online annotation tool that enables contributors to delineate the shapes of diffuse extended stellar structures with precision, as well as artifacts or foreground structures. All parameters are automatically stored in a database which may be queried to retrieve quantitative measurements. We annotated LSB structures around 352 nearby massive galaxies with deep images obtained with the Canada-France-Hawaii Telescope as part of two large programs: Mass Assembly of early-Type GaLAxies with their fine Structures (MATLAS) and Ultraviolet Near Infrared Optical Northern Survey (UNIONS)/Canada-France Imaging Survey (CFIS). Each LSB structure was delineated and labeled according to its likely nature: stellar shells, streams associated with a disrupted satellite, tails that formed in major mergers, ghost reflections, or cirrus. Results. From our database containing 8441 annotations, the area, size, median surface brightness, and distance to the host of 228 structures were computed. The results confirm the fact that tidal structures defined as streams are thinner than tails, as expected by numerical simulations. In addition, tidal tails appear to exhibit a higher surface brightness than streams (by about 1 mag), which may be related to different survival times for the two types of collisional debris. We did not detect any tidal feature fainter than 27.5 mag arcsec −2 , while the nominal surface brightness limits of our surveys range between 28.3 and 29 mag arcsec −2 , a difference that needs to be taken into account when estimating the sensitivity of future surveys to identify LSB structures. Conclusions. We compiled an annotation database of observed LSB structures around nearby massive galaxies including tidal features that may be used for quantitative analysis and as a training set for machine learning algorithms.

show abstract

Probing Asymmetric Structures in the Outskirts of Galaxies

Cited by 20 publications

References 68 publications

MERGING GALAXIES WITH TIDAL TAILS IN COSMOS TO z = 1

MERGING GALAXIES WITH TIDAL TAILS IN COSMOS TO z = 1

Fine-grained photometric classification using multi-model fusion method with redshift estimation

Characterization of low surface brightness structures in annotated deep images

Contact Info

Product

Resources

About