2009A&A...494..949S


C.D.S. - SIMBAD4 rel 1.7 - 2020.10.19CEST18:30:42

2009A&A...494..949S - Astronomy and Astrophysics, volume 494, 949-967 (2009/2-2)

Extremely faint high proper motion objects from SDSS stripe 82. Optical classification spectroscopy of about 40 new objects.

SCHOLZ R.-D., STORM J., KNAPP G.R. and ZINNECKER H.

Abstract (from CDS):

By pushing the magnitude limit of high proper motion surveys beyond the limit of photographic Schmidt plates, we aim to discover nearby and very fast low-luminosity objects of different classes: cool white dwarfs (CWDs), cool subdwarfs (sd), and very low-mass stars and brown dwarfs at the very faint end of the main sequence (MS). The deep multi-epoch Sloan Digital Sky Survey data in a 275 square degree area along the celestial equator (SDSS stripe 82) allow us to search for extremely faint (i>21) objects with proper motions greater than 0.14 arcsec/yr. A reduced proper motion diagram Hz/(i-z) clearly reveals three sequences (MS, sd, CWD) where our faintest candidates are representative of the still poorly known bottom of each sequence. We classify 38 newly detected objects with low-resolution optical spectroscopy using FORS1 SO VLT. Together with our targets we observe six known L dwarfs in stripe 82, four (ultra)cool sd and one CWD as comparison objects. Distances and tangential velocities are estimated using known spectral type/absolute magnitude relations. All 22 previously known L dwarfs (and a few of the T dwarfs) in stripe 82 have been detected in our high proper motion survey. However, 11 of the known L dwarfs have smaller proper motions (0.01<µ<0.14arcsec/yr). Although stripe 82 was already one of the best investigated sky regions with respect to L and T dwarfs, we are able to classify 13 new L dwarfs. Two previously known L dwarfs have been reclassified by us. We have also found eight new M7.5-M9.5 dwarfs. The four new CWDs discovered by us are about 1-2mag fainter than those previously detected in SDSS data. All new L-type, late-M and CWD objects show thick disk and halo kinematics. Since our high-velocity late-M and L dwarfs do not show indications of low metallicity in their spectra, we conclude that there may be a population of ultracool halo objects with normal metallicities. There are 13 objects, mostly with uncertain proper motions, which we initially classified as mid-M dwarfs. Among them we have found 9 with an alternative subdwarf classification (sdM7 or earlier types), whereas we have not found any new spectra resembling the known ultracool (>sdM7) subdwarfs. Some M subdwarf candidates have been classified based on spectral indices with large uncertainties. We failed to detect new nearby (d<50pc) L dwarfs, probably because the SDSS stripe 82 area was already well-investigated before. With our survey we have demonstrated a higher efficiency in finding Galactic halo CWDs than previous searches. The space density of halo CWDs is according to our results about 1.5-3.0x10–5/pc3.

Abstract Copyright:

Journal keyword(s): stars: kinematics - stars: low-mass, brown dwarfs - stars: subdwarfs - strars: white dwarfs - Galaxy: halo - Galaxy: solar neighbourhood

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 - 2020
#notes
1 2MASS J00160844-0043021 BD* 00 16 08.44440 -00 43 02.1468           L5.5 8 0
2 2MASS J00191165+0030176 BD* 00 19 11.6508762288 +00 30 17.647632948           L0.4V 11 0
3 2MASS J00213884+0026058 BD* 00 21 38.84664 +00 26 05.8488           L1.5 3 0
4 ULAS J002422.93+002247.9 BD* 00 24 22.93320 +00 22 47.8164           T4.5 5 0
5 SDSS J002800.38+010252.0 BD* 00 28 00.35595 +01 02 52.1977           L0.0 2 0
6 CFBDS J003402-005206 BD* 00 34 02.77416 -00 52 06.8196           T8+/Y? 47 0
7 2MASS J00343531+0046337 LM* 00 34 35.31288 +00 46 33.7512           M8.0 2 0
8 SDSS J003550.48+004631.3 LM* 00 35 50.47115 +00 46 31.7363           M8.0 2 0
9 2MASS J00521232+0012172 BD* 00 52 12.32232 +00 12 17.2512           L4.5 6 0
10 SDSS J005349.11-011354.5 BD* 00 53 49.11605 -01 13 53.9908           L0.0 2 0
11 2MASS J00540655-0031018 BD* 00 54 06.5797925021 -00 31 02.184077735           L2.2V 15 0
12 SDSS J005636.22-011131.9 BD* 00 56 36.24245 -01 11 31.6480           L1.5 3 0
13 SDSS J005837.48+004435.6 LM* 00 58 37.56960 +00 44 35.1456           M8.5 2 0
14 CFBDS J005910-011401 BD* 00 59 10.46265 -01 14 00.5404           T9.0 35 0
15 2MASS J01040750-0053283 BD* 01 04 07.50744 -00 53 28.3704           L5.0 10 1
16 2MASS J01075242+0041563 BD* 01 07 52.42200 +00 41 56.3964           L8 46 0
17 SDSS J010959.91-010156.3 WD* 01 09 59.91048 -01 01 56.3052           D 2 0
18 SDSS J011014.30+010619.1 BD* 01 10 14.22432 +01 06 19.2164           L4.0 2 0
19 SDSS J011755.09+005220.0 LM* 01 17 55.091 +00 52 20.05           M5.0/sdM7: 2 0
20 ULAS J013117.53-003128.6 BD* 01 31 17.48076 -00 31 29.2478           T3 2 0
21 SDSS J013415.85+001456.0 LM* 01 34 15.88560 +00 14 55.8384           M5.5 2 0
22 ULAS J013939.77+004813.8 BD* 01 39 39.78096 +00 48 13.9248           T7.5 6 0
23 SDSS J014956.27+001647.8 BD* 01 49 56.31144 +00 16 47.7948           L0.5 4 0
24 CD-28 595 PM* 01 54 50.2704861570 -27 28 35.740415025   12.06 11.51     ~ 120 0
25 BRLT 44 BD* 02 03 33.34488 -01 08 12.4548           L5.0 7 0
26 ULAS J020336.94-010231.1 BD* 02 03 36.94272 -01 02 31.3080           T5 5 0
27 SDSS J020508.03+002458.8 WD* 02 05 08.03808 +00 24 58.8348           D 2 0
28 2MASS J02074284+0000564 BD* 02 07 42.84984 +00 00 56.4408           T4.5 35 0
29 SDSS J021546.76+010019.2 LM* 02 15 46.77240 +01 00 19.2204           M5p:/esd:M3.5: 2 0
30 ULAS J022637.55+005154.3 BD* 02 26 37.55520 +00 51 54.3816           T3 8 0
31 SDSS J022723.77-005518.6 LM* 02 27 23.76624 -00 55 18.6564           M8 4 0
32 2MASS J02361794+0048548 BD* 02 36 17.94024 +00 48 54.8208           L6V 17 0
33 SDSS J024958.88+010624.3 LM* 02 49 58.91496 +01 06 23.8464           M5.0/sdM7 2 0
34 SDSS J025316.07+005157.1 LM* 02 53 16.06968 +00 51 57.1608           M4.5 2 0
35 2MASS J02560189+0110467 BD* 02 56 01.89192 +01 10 46.7112           L0V 9 0
36 SDSS J030136.53+002057.6 BD* 03 01 36.52657 +00 20 58.0569           L1 4 0
37 2MASS J03032123-0009378 LM* 03 03 21.2579035410 -00 09 38.156802236           M8V 9 0
38 SDSS J031049.53-011035.3 WD* 03 10 49.5413255820 -01 10 35.238907093           DC 7 0
39 SDSS J032129.21+003212.8 WD* 03 21 29.21040 +00 32 12.8436           D 2 0
40 2MASS J03281738+0032572 BD* 03 28 17.38512 +00 32 57.2316           L2.5:V 10 0
41 2MASS J03301774+0000477 BD* 03 30 17.74320 +00 00 47.7540           L0:V 5 0
42 2MASS J03303511-0025346 BD* 03 30 35.1456788629 -00 25 34.948452345           L2 19 0
43 SDSS J033203.57+003658.0 LM* 03 32 03.57744 +00 36 57.8988           M5.5/sdM7: 2 0
44 SDSS J033456.32+010618.6 BD* 03 34 56.45400 +01 06 18.3384           L0.5 3 0
45 LP 944-20 LM* 03 39 35.2525168530 -35 25 43.628465433     18.69 16.39 13.288 M9.5Ve 263 0
46 ULAS J034832.97-001258.3 BD* 03 48 32.92825 -00 12 57.4783           T 2 0
47 2MASS J03544855-0027420 BD* 03 54 48.55128 -00 27 42.0408           L2 5 0
48 LEHPM 2-59 PM* 04 52 09.9527810872 -22 45 09.343103916       18.82 17.22 esdM8.5 10 0
49 L 595-22 PM* 05 56 24.7419816722 -27 51 32.362978169   12.31 12.38     sdG 144 0
50 LSPM J0822+1700 LM* 08 22 33.7510263993 +17 00 18.931432210       18.7   usdM7.5 15 0
51 CD-32 5613 WD* 08 41 32.4293043356 -32 56 32.916852010   12.07 11.85 12.3   DA5.5 266 0
52 SSSPM J1013-1356 LM* 10 13 07.3466815701 -13 56 21.261098713       18.73 16.01 sdM9.5 34 0
53 G 11-35 LM* 12 02 33.6593915754 +08 25 50.731714280   15.58   13.2   sdM2.0 27 0
54 2MASS J12563716-0224522 BD* 12 56 37.1381711583 -02 24 52.253650704           esdL3.5 32 0
55 SDSS J133739.40+000142.9 WD* 13 37 39.4074914688 +00 01 42.661004966   20.03       DC 29 0
56 LP 440-52 LM* 14 39 00.3087274496 +18 39 38.704121134   19.6 18.39 17.3 14.64 sdM7 58 0
57 BD+19 2836 * 14 39 44.2799980320 +19 07 20.385323450   11.5 11.3     ~ 14 0
58 LSR J1610-0040 LM* 16 10 28.9562440851 -00 40 53.300190959       17.51 14.81 sdM7 46 0
59 EGGR 542 WD* 16 32 42.2384965086 +24 26 56.385477838   20.3   18.9   DC 13 0
60 LP 139-14 LM* 17 39 51.3972713142 +51 27 17.487647528   19.4   16.9   usdM4 28 0
61 2MASS J20282035+0052265 BD* 20 28 20.3586416021 +00 52 26.511094674           L2.5 29 0
62 SDSS J204821.28-004734.1 LM* 20 48 21.28752 -00 47 34.1592           M4.5 2 0
63 CFBDS J212413+010002 BD* 21 24 13.87968 +00 59 59.9172           T6 20 0
64 SDSS J213151.87-001432.4 BD* 21 31 51.89592 -00 14 33.3312           L0.0 2 0
65 2MASS J21404654+0112594 BD* 21 40 46.54200 +01 12 59.4144           L4.4V 10 0
66 SDSS J215322.18-004553.9 PM* 21 53 22.18392 -00 45 53.9856           M4.5/sdM7: 2 0
67 SDSS J215351.20+010120.3 LM* 21 53 51.20040 +01 01 20.3484           M4.0 2 0
68 SDSS J215515.49+005128.0 LM* 21 55 15.49944 +00 51 28.1628           M5.0/sdM7 2 0
69 SDSS J215817.69+000300.3 BD* 21 58 17.70816 +00 02 59.9064           L1.5 3 0
70 SDSS J215934.25+005308.5 LM* 21 59 34.27200 +00 53 08.4444           M9.5 2 0
71 * eps Ind B BD* 22 04 10.52064 -56 46 57.7452     24.12 20.8 15.60 T1V+T6V 132 2
72 SDSS J220952.49+003325.2 LM* 22 09 52.47624 +00 33 25.2216           M4.5/sdM7: 2 0
73 SDSS J221911.35+010220.5 LM* 22 19 11.35944 +01 02 20.6952           M3.5/sdM2: 2 0
74 SDSS J222939.14+010405.5 WD* 22 29 39.21384 +01 04 05.3652           D 2 0
75 BRLT 311 BD* 22 29 58.30512 +01 02 17.2428           T3.0 6 0
76 ULAS J223955.76+003252.6 BD* 22 39 55.75896 +00 32 52.6524           T5.5 8 0
77 2MASS J22495345+0044046 BD* 22 49 53.45592 +00 44 04.6608           L3+L5 40 0
78 2MASS J22552907-0034336 LM* 22 55 29.0850402031 -00 34 33.682922600     20.26     M8.6V 26 1
79 SDSS J225903.29-004154.2 LM* 22 59 03.26893 -00 41 53.9174           M8.0 2 0
80 2MASS J22591388-0051581 BD* 22 59 13.88904 -00 51 58.1652           L1.6V 6 0
81 SDSS J230722.58-005746.6 BD* 23 07 22.56191 -00 57 46.6120           L1.0 3 0
82 SDSS J231407.82+004908.2 LM* 23 14 07.83240 +00 49 08.0616           M8.0 2 0
83 SDSS J231914.40+005615.9 LM* 23 19 14.40672 +00 56 15.9324           M5.5/sdM7 2 0
84 SDSS J232935.99-011215.3 LM* 23 29 35.96938 -01 12 14.9612           M7.5 2 0
85 DENIS J234539.0+005514 LM* 23 45 39.0315449870 +00 55 13.728586050         16.902 M9V 15 0
86 SDSS J234841.38-004022.2 BD* 23 48 41.37583 -00 40 21.5962           L1.5 3 0
87 SDSS J235826.48+003226.9 LM* 23 58 26.42538 +00 32 26.4871           M8.0 2 0
88 SDSS J235835.45-000909.5 BD* 23 58 35.46914 -00 09 09.2620           L0.0 2 0
89 2MASS J23584196+0006212 BD* 23 58 41.96952 +00 06 21.2940           L1.5 3 0

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2020.10.19-18:30:42

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