2020A&A...641A..77C


C.D.S. - SIMBAD4 rel 1.7 - 2020.11.28CET21:48:39

2020A&A...641A..77C - Astronomy and Astrophysics, volume 641A, 77-77 (2020/9-1)

Bars formed in galaxy merging and their classification with deep learning.

CAVANAGH M.K. and BEKKI K.

Abstract (from CDS):


Context. Stellar bars are a common morphological feature of spiral galaxies. While it is known that they can form in isolation, or be induced tidally, few studies have explored the production of stellar bars in galaxy merging. We look to investigate bar formation in galaxy merging using methods from deep learning to analyse our N-body simulations.
Aims. The primary aim is to determine the constraints on the mass ratio and orientations of merging galaxies that are most conducive to bar formation. We further aim to explore whether it is possible to classify simulated barred spiral galaxies based on the mechanism of their formation. We test the feasibility of this new classification schema with simulated galaxies.
Methods. Using a set of 29400 images obtained from our simulations, we first trained a convolutional neural network to distinguish between barred and non-barred galaxies. We then tested the network on simulations with different mass ratios and spin angles. We adapted the core neural network architecture for use with our additional aims.
Results. We find that a strong inverse relationship exists between the mass ratio and the number of bars produced. We also identify two distinct phases in the bar formation process; (1) the initial, tidally induced formation pre-merger and (2) the destruction and/or regeneration of the bar during and after the merger .
Conclusions. Mergers with low mass ratios and closely-aligned orientations are considerably more conducive to bar formation compared to equal-mass mergers. We demonstrate the flexibility of our deep learning approach by showing it is feasible to classify bars based on their formation mechanism.

Abstract Copyright: © ESO 2020

Journal keyword(s): galaxies: general - galaxies: formation - galaxies: evolution

Simbad objects: 1

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Number of rows : 1

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 Cl Melotte 22 OpC 03 47 00 +24 07.0           ~ 3037 0

    Equat.    Gal    SGal    Ecl

C.D.S. - SIMBAD4 rel 1.7 - 2020.11.28CET21:48:39

Available data : Basic data  •  Identifiers  •  Plot & images  •  Bibliography  •  Measurements  •  External archives  •  Notes  •  Annotations


Basic data :
Cl Melotte 22 -- Open (galactic) Cluster
Origin of the objects types :

(Ref) Object type as listed in the reference "Ref"
(acronym) Object type linked to the acronym according to the original reference
() Anterior to 2007, before we can link the objet type to a reference, or given by the CDS team in some particular cases

Other object types:
Cl* (C,Cl,...), OpC (2013A&A,OCl), X (H)
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
ICRS coord. (ep=J2000) :
03 47 00.0 +24 07 00 (Optical) [ ] E 2009MNRAS.399.2146W
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
FK4 coord. (ep=B1950 eq=1950) :
03 44 01.4 +23 57 47 [ ]
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
Gal coord. (ep=J2000) :
166.5707 -23.5212 [ ]
Syntax of proper motions is : "pm-ra pm-dec [error ellipse] quality bibcode"
  • pm-ra : mu-ra*cos(dec) (expressed in the ICRS system in mas/yr)
  • pm-dec : mu-dec (expressed in the ICRS system in mas/yr)
  • [error ellipse] : error major axis and minor axis (in mas), orientation angle (in deg)
  • quality : flag of quality (A=best quality -> E=worst quality, {� } =unknown quality)
  • bibcode : bibcode of the proper motion reference
Proper motions mas/yr :
19.997 -45.548 [0.127 0.101 90] B 2018A&A...616A..10G
Syntax of radial velocity (or/and redshift) is : "value [error] (wavelength) quality bibcode"
  • value : radial velocity or/and redshift (Heliocentric frame) according to your Output Options
    (redshift may be not displayed if the data value is <0 and the database inside value is a radial velocity)
  • [error] : error of the corresponding value displayed before
  • (wavelength) : wavelength range of the measurement : Rad, mm, IR, Opt, UV, Xray, Gam or  '∼'(unknown)
  • quality : flag of quality ( A=best quality -> E=worst quality, {� } =unknown quality)
  • bibcode : bibcode of the value's origin
Radial velocity / Redshift / cz :
V(km/s) 6.57 [0.17] / z(spectroscopic) 0.000022 [0.000001] / cz 6.57 [0.17]
   (NIR) A 2019A&A...623A..80C
Syntax of parallax is : 'value quality [error] bibcode'
  • value : parallax value
  • quality : flag of quality (A=best quality -> E=worst quality, {� } =unknown quality)
  • [error] : mean error
  • bibcode : bibcode of the parallax reference
Parallaxes (mas):
7.364 [0.005] B 2018A&A...616A..10G
Syntax of angular size is : "maj-axis min-axis angle (wtype) quality bibcode"
  • maj-axis : major axis size (arc minutes)
  • min-axis : minor axis size (arc minutes)
  • angle : orientation angle (in degrees)
  • (wtype) : wavelength class for the origin of the angular size (Rad, mm, IR, Opt, UV, Xray, Gam)
  • quality : flag of quality of the angular size values ( A=best quality -> E=worst quality, {� } =unknown quality)
  • bibcode : bibcode of the angular size reference
Angular size (arcmin):
1200 1200 90 (Opt) D 2009PASP..121..450B
SIMBAD with radius arcmin
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Hierarchy : number of linked objects
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: 4043
Display criteria :

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Identifiers (9) :
An access of full data is available using the icon Vizier near the identifier of the catalogue

M 45 H 0346+24 OCl 421.0
C 0344+239 NAME Pleiades [KPR2004b] 47
Cl Melotte 22 NAME Seven Sisters [KPS2012] MWSC 0305

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References (3037 between 1850 and 2021) (Total 3037)
Simbad bibliographic survey began in 1850 for stars (at least bright stars) and in 1983 for all other objects (outside the solar system).
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Collections of Measurements


distance : 2    velocities : 4    PM : 3    Fe_H : 3    PLX : 3   

   

Observing logs


ISO : 23    XMM : 4   

   


External archives :

Archive data at HEASARC - High-Energy Astrophysics Science Archive Research Center

Data at NED - NASA/IPAC Extragalactic Database : Cl Melotte 22


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2020.11.28-21:48:39

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