During original visual classification of z = 0.7 galaxies in GEMS, 141 were placed in class 6 = Pec/Int (see table).
| Morpho. class | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | > 7 | All |
| E | S0 | Sa | Sbc | Sdm | Irr | Pec/Int | Compact | Other | All |
| Number | 219 | 86 | 57 | 214 | 347 | 300 | 142 | 15 | 2 | 1382 |
| No. w/ A > 0.35 | 6 | 3 | 2 | 8 | 3 | 16 | 20 | 1 | 0 | 59 |
| % w/ A > 0.35 | 2.7 | 3.5 | 3.5 | 3.7 | 0.9 | 5.3 | 14.1 | 6.7 | 0 | 4.3 |
But class 6 does not distinguish between faint vs. bright or strong vs. weak morphological distortions. We visually reclassified all class 6 objects into more specific sub-classes that distinguish between these types of distortions. The goals were to:
- determine visually how many class 6 (Pec/Int) galaxies are actually strongly interacting systems.
- estimate for all galaxies quantitative asymmetry parameters, such as CAS A (Conselice et al 2000).
- determine what fraction of galaxies in each sub-class turn out to have CAS A > A1, where A1 is some critical value. A1 is often taken as 0.35 in order to identify major mergers and disturbance, but we revisit this assumption.
MC 61 = pronounced bright morphological disturbance.
MC 63 = moderate bright morphological disturbance.
MC 62 = pronounced faint morphological disturbance.
MC 64 = moderate to very subtle faint morphological disturbance.
MC 65 = no clear sign of morphological disturbance.
MC 67 = irregular galaxy with multiple UV peaks (HII regions) that appear to be distributed in rings or slightly irregular configurations within a larger underlying disk feature. These are different from double nuclei cases of 61 or 63.
where
- class 61 and 63 (pronounced/moderate bright morphological disturbance) refer to double nuclei, highly asymmetric inner regions + star formation (as is present before violent relaxation kicks in), and pronounced tidal tails.
- class 62 and 64 refer to faint features only. These features may be similar to those in class 61 and 63 except that they appear only at faint levels and are less extreme e.g., faint arcs and shells and faint tidal tails.
Gzipped tar file containing summary of method, results, tables, and figures. We assume throughout a Lambda_CDM flat cosmology with Omega_M = 0.3, Omega_Lambda = 0.7, and H0 = 70 km s-1 Mpc-1.
Below are gifs of all 141 galaxies, subdivided by morphological class and asymmetry:
61 63
62 64
65 67
Morph. class 61
MC 61 = pronounced bright morphological disturbance.
Below are CAS asymmetry parameters (A) and F606W images of GEMS galaxies at z = 0.7, which we have visually classified into morphological class (MC) 61.
The first subset of images has A > 0.35 and the second subset has A < 0.35. The caption includes id, unique GEMS id, and A.
The images show ~210 x 210 pixels or 6.3" x 6.3", which corresponds to 45 kpc x 45 kpc at z = 0.7. At z = 0.7, F606W (pivot = 5916 A) corresponds to rest-frame far UV-B (pivot = 3479 A) images.
A > 0.35
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| 1, 033130.05m275602.3, 0.540 | 2, 033320.18m273503.1, 0.479 |
A < 0.35
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| 1, 033317.99m275805.0, 0.215 | 2, 033206.51m275658.9, 0.211 | 3, 033205.33m280300.2, 0.085 |
Morph. class 62
MC 62 = pronounced faint morphological disturbance.
Below are CAS asymmetry parameters (A) and F606W images of GEMS galaxies at z = 0.7, which we have visually classified into MC 62.
The first subset of images has A > 0.35 and the second subset has A < 0.35. The caption includes id, unique GEMS id, and A.
The images show ~210 x 210 pixels or 6.3" x 6.3", which corresponds to 45 kpc x 45 kpc at z = 0.7. At z = 0.7, F606W (pivot = 5916 A) corresponds to rest-frame far UV-B (pivot = 3479 A) images.
None with A > 0.35.
A < 0.35
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| 1, 033249.36m273718.7, 0.318 | 2, 033309.10m275846.1, 0.318 | 3, 033130.47m275951.5, 0.310 | 4, 033151.63m275338.2, 0.289 | 5, 033131.29m275935.8, 0.248 |
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| 6, 033231.35m274724.9, 0.217 | 7, 033236.50m274629.3, 0.180 | 8, 033221.21m273534.3, -0.040 | 9, 033154.04m275005.8, 0.000 |
Morph. class 63
MC 63 = moderate bright morphological disturbance.
Below are CAS asymmetry parameters (A) and F606W images of GEMS galaxies at z = 0.7, which we have visually classified into MC 63.
The first subset of images has A > 0.35 and the second subset has A < 0.35. The caption includes id, unique GEMS id, and A.
The images show ~210 x 210 pixels or 6.3" x 6.3", which corresponds to 45 kpc x 45 kpc at z = 0.7. At z = 0.7, F606W (pivot = 5916 A) corresponds to rest-frame far UV-B (pivot = 3479 A) images.
A > 0.35
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| 1, 033219.95m273452.9, 0.488 | 2, 033152.30m273615.9, 0.462 | 3, 033223.03m275452.3, 0.448 | 4, 033212.25m274046.2, 0.439 | 5, 033136.90m274959.3, 0.438 |
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| 6, 033149.02m273945.3, 0.427 | 7, 033320.72m274927.6, 0.424 | 8, 033257.96m274023.6, 0.366 |
A < 0.35
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| 1, 033151.21m275037.6, 0.323 | 2, 033247.31m274247.9, 0.304 | 3, 033317.03m280126.4, 0.304 | 4, 033204.51m280153.5, 0.304 | 5, 033247.47m273926.2, 0.301 |
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| 6, 033133.22m274208.7, 0.300 | 7, 033202.27m274007.3, 0.292 | 8, 033148.09m280232.2, 0.291 | 9, 033236.16m273955.7, 0.283 | 10, 033156.72m275636.1, 0.278 |
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| 11, 033247.50m280258.6, 0.277 | 12, 033126.83m274249.9, 0.273 | 13, 033300.47m275908.5, 0.272 | 14, 033151.48m275024.5, 0.272 | 15, 033212.51m274454.7, 0.252 |
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| 16, 033148.35m280315.8, 0.250 | 17, 033230.59m274518.1, 0.234 | 18, 033133.99m273718.0, 0.232 | 19, 033239.18m280208.8, 0.229 | 20, 033206.78m274921.6, 0.224 |
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| 21, 033241.06m280250.8, 0.217 | 22, 033319.05m275658.8, 0.216 | 23, 033323.90m273931.3, 0.210 | 24, 033209.77m273525.6, 0.209 | 25, 033245.82m273443.3, 0.206 |
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| 26, 033138.03m273658.0, 0.182 | 27, 033203.17m273839.7, 0.162 | 28, 033234.89m280045.7, 0.151 | 29, 033253.50m280333.9, 0.150 | 30, 033151.04m273933.3, 0.143 |
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| 31, 033233.50m280040.0, 0.140 | 32, 033133.76m274822.0, 0.098 | 33, 033240.60m273715.8, 0.066 | 34, 033209.69m275600.5, -0.010 | 35, 033219.07m280252.8, 0.008 |
Morph. class 64
MC 64 = moderate to very subtle faint morphological disturbance.
Below are CAS asymmetry parameters (A) and F606W images of GEMS galaxies at z = 0.7, which we have visually classified into MC 64.
The first subset of images has A > 0.35 and the second subset has A < 0.35. The caption includes id, unique GEMS id, and A.
The images show ~210 x 210 pixels or 6.3" x 6.3", which corresponds to 45 kpc x 45 kpc at z = 0.7. At z = 0.7, F606W (pivot = 5916 A) corresponds to rest-frame far UV-B (pivot = 3479 A) images.
A > 0.35
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| 1, 033250.20m275552.2, 0.422 | 2, 033154.75m275006.9, 0.372 | 3, 033134.43m274329.1, 0.365 | 4, 033149.20m274933.0, 0.358 |
A < 0.35
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| 1, 033310.21m274305.3, 0.340 | 2, 033321.80m280344.3, 0.340 | 3, 033149.06m275359.5, 0.323 | 4, 033210.36m275332.8, 0.319 | 5, 033207.90m275329.6, 0.315 |
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| 6, 033135.63m274701.5, 0.308 | 7, 033235.37m273519.1, 0.287 | 8, 033318.59m275900.5, 0.283 | 9, 033149.90m275018.2, 0.264 | 10, 033254.91m274038.0, 0.246 |
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| 11, 033307.50m274201.3, 0.243 | 12, 033203.11m273933.2, 0.226 | 13, 033153.04m275606.7, 0.225 | 14, 033128.34m275634.3, 0.222 | 15, 033145.56m275625.8, 0.216 |
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| 16, 033158.25m275456.6, 0.209 | 17, 033320.51m280034.9, 0.192 | 18, 033212.63m280054.5, 0.187 | 19, 033144.08m273627.2, 0.181 | 20, 033151.46m273945.5, 0.174 |
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| 21, 033254.55m275905.5, 0.171 | 22, 033233.74m273612.5, 0.167 | 23, 033122.61m280105.5, 0.163 | 24, 033149.04m275402.2, 0.160 | 25, 033308.34m273858.4, 0.149 |
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| 26, 033202.20m275500.0, 0.148 | 27, 033221.84m273824.9, 0.147 | 28, 033258.88m274806.0, 0.105 | 29, 033240.38m280342.8, 0.098 | 30, 033202.56m275231.3, 0.093 |
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| 31, 033229.44m275538.2, 0.080 | 32, 033257.54m275908.8, 0.080 | 33, 033227.34m273850.9, 0.071 | 34, 033208.78m275058.5, 0.054 | 35, 033302.32m280032.9, -0.050 |
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| 36, 033158.42m280318.7, 0.041 | 37, 033152.78m274928.5, -0.040 | 38, 033132.20m275045.9, 0.039 | 39, 033140.59m274019.6, 0.038 |
Morph. class 65
MC 65 = no clear sign of morphological disturbance.
Below are CAS asymmetry parameters (A) and F606W images of GEMS galaxies at z = 0.7, which we have visually classified into MC 65.
The first subset of images has A > 0.35 and the second subset has A < 0.35. The caption includes id, unique GEMS id, and A.
The images show ~210 x 210 pixels or 6.3" x 6.3", which corresponds to 45 kpc x 45 kpc at z = 0.7. At z = 0.7, F606W (pivot = 5916 A) corresponds to rest-frame far UV-B (pivot = 3479 A) images.
A > 0.35
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| 1, 033230.93m274058.4, 0.564 | 2, 033132.05m274903.9, 0.436 | 3, 033229.64m274242.5, 0.429 | 4, 033145.47m275446.2, 0.360 |
A < 0.35
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| 1, 033225.40m275633.8, 0.341 | 2, 033202.86m280237.2, 0.300 | 3, 033153.73m275422.1, 0.281 | 4, 033314.82m275919.8, 0.270 | 5, 033137.45m274145.3, 0.250 |
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| 6, 033245.52m273840.2, 0.240 | 7, 033131.01m274140.1, 0.223 | 8, 033301.78m275225.8, 0.211 | 9, 033218.25m275225.0, 0.200 | 10, 033205.36m273532.6, 0.181 |
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| 11, 033125.49m275518.1, 0.162 | 12, 033216.61m280039.2, 0.150 | 13, 033154.99m275651.2, 0.133 | 14, 033232.71m274859.5, 0.106 | 15, 033309.04m273943.8, 0.100 |
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| 16, 033207.83m280144.6, 0.097 | 17, 033132.80m274608.7, 0.092 | 18, 033253.03m280153.3, 0.090 | 19, 033306.14m280204.3, 0.085 | 20, 033221.07m273529.9, 0.072 |
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| 21, 033145.67m275438.0, 0.071 | 22, 033151.28m275828.5, 0.061 | 23, 033131.05m280145.3, 0.061 | 24, 033310.98m280316.0, 0.051 | 25, 033207.17m273456.9, 0.042 |
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| 26, 033216.16m274941.6, 0.013 | 27, 033308.18m275033.1, -0.000 |
Morph. class 67
MC 67 = irregular galaxy with multiple UV peaks (HII regions) that appear to be distributed in rings or slightly irregular configurations within a larger underlying disk feature. These are different from double nuclei cases of 61 or 63.
Below are CAS asymmetry parameters (A) and F606W images of GEMS galaxies at z = 0.7, which we have visually classified into MC 67.
The first subset of images has A > 0.35 and the second subset has A < 0.35. The caption includes id, unique GEMS id, and A.
The images show ~210 x 210 pixels or 6.3" x 6.3", which corresponds to 45 kpc x 45 kpc at z = 0.7. At z = 0.7, F606W (pivot = 5916 A) corresponds to rest-frame far UV-B (pivot = 3479 A) images.
A > 0.35
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| 1, 033221.19m273454.6, 0.553 | 2, 033236.78m273452.2, 0.373 |
A < 0.35
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| 1, 033214.76m280013.3, 0.319 | 2, 033123.51m275602.7, 0.235 | 3, 033158.91m274712.1, 0.176 | 4, 033137.44m273643.1, 0.124 | 5, 033207.96m280103.1, 0.124 |
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| 6, 033211.22m280245.8, 0.083 | 7, 033255.93m275356.9, 0.074 | 8, 033221.42m275616.9, 0.033 |