2020ApJ...901..123F

Query : 2020ApJ...901..123F

2020ApJ...901..123F - Astrophys. J., 901, 123-123 (2020/October-1)

Using machine learning to find ghostly damped Lyα systems in the SDSS DR14.

FATHIVAVSARI H.

Abstract (from CDS):

We report the discovery of 59 new ghostly absorbers from the Sloan Digital Sky Survey Data Release 14. These absorbers, with zabs ∼ zQSO, reveal no Lyα absorption, and they are mainly identified through the detection of strong metal absorption lines in the spectra. The number of such previously known systems is 30. The new systems are found with the aid of machine-learning algorithms. The spectra of 41 (out of total of 89) absorbers also cover the Lyβ spectral region. By fitting the damping wings of the Lyβ absorption in the stacked spectrum of 21 (out of 41) absorbers with relatively stronger Lyβ absorption, we measured an H I column density of log N(H I) = 21.50. This column density is 0.5 dex higher than that of the previous work. We also found that the metal absorption lines in the stacked spectrum of the 21 ghostly absorbers with stronger Lyβ absorption have similar properties as those in the stacked spectrum of the remaining systems. This circumstantial evidence strongly suggests that the majority of our ghostly absorbers are indeed DLAs.

Abstract Copyright: © 2020. The American Astronomical Society. All rights reserved.

Journal keyword(s): Interstellar absorption - Interstellar line absorption - Quasars - Quasar absorption line spectroscopy - Active galactic nuclei - Intergalactic medium - Circumgalactic medium

VizieR on-line data: <Available at CDS (J/ApJ/901/123): table5.dat>

Simbad objects: 89

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Number of rows : 89
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026 		#notes
1 SDSS J000125.69+141022.3 QSO 00 01 25.6938277968 +14 10 22.415705652           ~ 7 0
2 SDSS J000943.73+132032.6 QSO 00 09 43.7346885240 +13 20 32.685292284           ~ 6 0
3 [VV96] J000958.7+015754 QSO 00 09 58.6568885424 +01 57 55.157472324     19.6     ~ 30 1
4 SDSS J001245.12-054945.7 QSO 00 12 45.1272241656 -05 49 45.718927176           ~ 7 0
5 SDSS J001316.82-093841.2 QSO 00 13 16.8208704240 -09 38 41.258636232           ~ 6 0
6 SDSS J002144.10+172601.1 QSO 00 21 44.1103561128 +17 26 01.251459348           ~ 7 0
7 SDSS J003606.10+272539.2 QSO 00 36 06.106 +27 25 39.28           ~ 7 0
8 SDSS J003901.47+073434.2 QSO 00 39 01.4685770424 +07 34 34.223827008           ~ 7 0
9 SDSS J004703.08+140228.8 QSO 00 47 03.0884411160 +14 02 28.790550708           ~ 6 0
10 SDSS J005321.17+112240.6 QSO 00 53 21.172 +11 22 40.69           ~ 7 0
11 SDSS J005343.38+125659.6 QSO 00 53 43.384 +12 56 59.70           ~ 8 0
12 SDSS J011145.03-030138.6 QSO 01 11 45.0350604864 -03 01 38.644880520           ~ 8 0
13 SDSS J011449.21+003522.9 QSO 01 14 49.212 +00 35 22.95           ~ 7 0
14 SDSS J011521.95+183744.4 QSO 01 15 21.960 +18 37 44.52           ~ 8 0
15 SDSS J011608.04+205523.7 QSO 01 16 08.0502975816 +20 55 23.719851336           ~ 7 0
16 SDSS J012703.47+033849.4 QSO 01 27 03.4800594000 +03 38 49.386763140           ~ 7 0
17 SDSS J022227.99+000523.8 QSO 02 22 27.996 +00 05 23.89           ~ 8 0
18 SDSS J075300.66+324858.1 QSO 07 53 00.6689178720 +32 48 58.233483792           ~ 8 0
19 SDSS J080828.04+125331.3 QSO 08 08 28.0458149376 +12 53 31.332018984           ~ 8 0
20 SDSS J082726.75+214557.0 QSO 08 27 26.7602308176 +21 45 57.116653092           ~ 12 0
21 SDSS J082839.98+232824.5 QSO 08 28 39.9827047032 +23 28 24.544811496           ~ 6 0
22 SDSS J083148.71+020505.9 QSO 08 31 48.7167017424 +02 05 05.979112008           ~ 7 0
23 SDSS J083444.52+150506.9 QSO 08 34 44.5214024472 +15 05 06.998991252           ~ 10 0
24 6C 090043+561354 QSO 09 04 24.0806655336 +56 02 05.501994576           ~ 11 1
25 SDSS J091103.72+124433.3 QSO 09 11 03.7291607856 +12 44 33.306969804           ~ 8 0
26 SDSS J091213.10+490750.8 QSO 09 12 13.107 +49 07 50.89           ~ 7 0
27 SDSS J091714.88+025223.0 QSO 09 17 14.8874481624 +02 52 23.076933240           ~ 11 0
28 SDSS J092334.18+102927.7 QSO 09 23 34.1806824000 +10 29 27.803530104           ~ 7 0
29 [VV2006] J093751.6+073041 QSO 09 37 51.5981020296 +07 30 41.275591308   21.26 20.68     ~ 24 0
30 SDSS J094001.85+493013.8 QSO 09 40 01.8581286960 +49 30 13.799633436           ~ 8 0
31 6C 093900+375213 QSO 09 42 03.5466923976 +37 38 20.772292380           ~ 11 2
32 QSO J0952+0114 QSO 09 52 53.8407789936 +01 14 22.066303020   19.88 19.38     ~ 41 0
33 SDSS J095701.16+352345.2 QSO 09 57 01.1657348064 +35 23 45.318506748           ~ 8 0
34 SDSS J100448.14+524043.7 QSO 10 04 48.1431335472 +52 40 43.768944876           ~ 8 0
35 6C 101044+343724 QSO 10 13 36.2247868944 +34 23 17.694903588           ~ 17 1
36 SDSS J101422.86+265339.6 QSO 10 14 22.8722355768 +26 53 39.671882304           ~ 9 0
37 SDSS J102552.86+234937.8 QSO 10 25 52.8624943488 +23 49 37.880793984           ~ 8 0
38 SDSS J102851.61+640827.9 QSO 10 28 51.6055826472 +64 08 27.755722104           ~ 7 0
39 SDSS J104141.18+570958.3 QSO 10 41 41.1954267192 +57 09 58.029020892           ~ 10 0
40 SDSS J105536.14+145808.6 QSO 10 55 36.1487355120 +14 58 08.657754708           ~ 6 0
41 SDSS J110706.91-003356.4 QSO 11 07 06.9123479880 -00 33 56.381635440           ~ 8 0
42 SDSS J110709.51+144712.7 QSO 11 07 09.5101716216 +14 47 12.710879700           ~ 7 0
43 SDSS J111649.38+365519.6 QSO 11 16 49.3804001376 +36 55 19.655924196           ~ 9 0
44 6C 111639+522043 QSO 11 19 29.18267 +52 04 07.5972           ~ 14 1
45 SDSS J112557.03-002529.0 QSO 11 25 57.0371183832 -00 25 29.056637496           ~ 9 0
46 SDSS J112655.18+661715.0 QSO 11 26 55.1859774312 +66 17 14.784831096           ~ 9 0
47 [VV2006] J112930.7+441941 QSO 11 29 30.7487822064 +44 19 41.437104456   19.94 19.48     ~ 23 0
48 SDSS J114343.37+631623.2 QSO 11 43 43.3990429032 +63 16 22.939683816           ~ 7 0
49 SDSS J120749.33+514407.6 QSO 12 07 49.3377520344 +51 44 07.633271076           ~ 10 0
50 SDSS J121843.73+135224.2 QSO 12 18 43.7321076432 +13 52 24.307322268           ~ 6 0
51 SDSS J121912.05+095040.2 QSO 12 19 12.058 +09 50 40.23           ~ 8 0
52 SDSS J122535.26+372816.7 QSO 12 25 35.2635778848 +37 28 16.682306052           ~ 8 0
53 SDSS J123135.56+154601.6 QSO 12 31 35.5610345472 +15 46 01.718418900           ~ 7 0
54 SDSS J123627.65+661738.0 QSO 12 36 27.6650918736 +66 17 37.735878444           ~ 8 0
55 [VV2006] J124202.0-002209 QSO 12 42 02.0371354608 -00 22 08.970090528     20.69     ~ 17 0
56 SDSS J124329.71+014438.8 QSO 12 43 29.7099451128 +01 44 38.764054572           ~ 7 0
57 SDSS J124847.63+332500.3 QSO 12 48 47.6320542552 +33 25 00.294081060           ~ 10 0
58 SDSS J125437.96+315530.8 QSO 12 54 37.9593337008 +31 55 30.882295236           ~ 10 0
59 SDSS J130136.44+514258.7 QSO 13 01 36.4399592400 +51 42 58.727792844           ~ 7 0
60 SDSS J130552.24+263300.0 QSO 13 05 52.2418397544 +26 32 59.964971208           ~ 10 0
61 SDSS J130709.52+072927.3 QSO 13 07 09.5202580608 +07 29 27.359002536           ~ 6 0
62 [VV2006] J133332.7+455606 QSO 13 33 32.7312944040 +45 56 06.194805720   19.89 19.59     ~ 22 0
63 SDSS J134020.36+030132.4 QSO 13 40 20.361 +03 01 32.38           ~ 7 0
64 SDSS J134103.38+490735.6 QSO 13 41 03.3785547024 +49 07 35.769964260           ~ 11 0
65 SDSS J134659.96+373454.1 QSO 13 46 59.9675973720 +37 34 54.224972472           ~ 8 0
66 SDSS J143440.58+623002.4 QSO 14 34 40.5901267224 +62 30 02.445764724   19.96 19.55     ~ 15 0
67 SDSS J143659.70+130223.6 QSO 14 36 59.7048719568 +13 02 23.737415424           ~ 7 0
68 SDSS J143705.63+403231.5 QSO 14 37 05.632 +40 32 31.53           ~ 8 0
69 SDSS J143725.05+351048.6 QSO 14 37 25.0579131216 +35 10 48.636157188       20.67 19.93 ~ 19 0
70 SDSS J150426.11+214559.4 QSO 15 04 26.1198173448 +21 45 59.412077424           ~ 8 0
71 SDSS J153005.44+174725.9 QSO 15 30 05.4428636352 +17 47 26.006320644           ~ 12 0
72 SDSS J153016.27+043927.5 QSO 15 30 16.2728047752 +04 39 27.545739336           ~ 8 0
73 6C 154024+530028 QSO 15 41 44.65471 +52 50 54.6964           ~ 9 1
74 SDSS J154206.05+113310.3 QSO 15 42 06.0523940064 +11 33 10.428601284           ~ 9 0
75 SDSS J161433.15+533249.4 QSO 16 14 33.1556944608 +53 32 49.492562568 21.04         ~ 8 0
76 SDSS J161549.79+284230.8 QSO 16 15 49.790 +28 42 30.84           ~ 7 0
77 SDSS J161928.21+120254.3 QSO 16 19 28.2183449232 +12 02 54.329978436           ~ 11 0
78 6C 163533+530138 QSO 16 36 46.2143920944 +52 55 40.560477888           ~ 12 2
79 SDSS J164850.00+272605.5 QSO 16 48 50.0007391800 +27 26 05.596330164           ~ 10 0
80 SDSS J173349.85+263338.0 QSO 17 33 49.8498466872 +26 33 38.010369096           ~ 9 0
81 SDSS J221810.45+234137.5 QSO 22 18 10.4571748584 +23 41 37.614758604           ~ 5 0
82 SDSS J222028.54+000531.6 QSO 22 20 28.549 +00 05 31.61           ~ 11 0
83 SDSS J222555.71+183350.4 QSO 22 25 55.722 +18 33 50.39           ~ 8 0
84 SDSS J224517.98+193101.9 QSO 22 45 17.9818546104 +19 31 01.870246236           ~ 7 0
85 SDSS J225051.48+221210.8 QSO 22 50 51.4814006448 +22 12 10.835047152           ~ 6 0
86 SDSS J232301.76+001510.1 QSO 23 23 01.765 +00 15 10.11           ~ 8 0
87 SDSS J234008.48+234209.4 QSO 23 40 08.4795990240 +23 42 09.369627372           ~ 9 0
88 SDSS J234351.30+340607.3 QSO 23 43 51.305 +34 06 07.34           ~ 7 0
89 SDSS J235533.83+252229.7 QSO 23 55 33.8347134240 +25 22 29.700107472           ~ 7 0

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