Two ultra-faint Milky Way stellar systems discovered in early data from the DECam Local Volume Exploration survey

DELVE Collaboration; S. Mau; W. Cerny; A. B. Pace; Y. Choi; A. Drlica-Wagner; L. Santana-Silva; A. H. Riley; D. Erkal; G. S. Stringfellow; M. Adamów; J. L. Carlin; R. A. Gruendl; D. Hernandez-Lang; D. Hernandez-Lang; N. Kuropatkin; T. S. Li; C. E. Martínez-Vázquez; E. Morganson; B. Mutlu-Pakdil; E. H. Neilsen; D. L. Nidever; K. A. G. Olsen; D. J. Sand; E. J. Tollerud; D. L. Tucker; B. Yanny; A. Zenteno; S. Allam; W. A. Barkhouse; K. Bechtol; E. F. Bell; P. Balaji; D. Crnojević; J. Esteves; P. S. Ferguson; C. Gallart; A. K. Hughes; D. J. James; P. Jethwa; L. C. Johnson; K. Kuehn; S. Majewski; Y. Y. Mao; P. Massana; M. McNanna; A. Monachesi; E. O. Nadler; N. E. D. Noël; A. Palmese; F. Paz-Chinchon; A. Pieres; J. Sanchez; N. Shipp; J. D. Simon; M. Soares-Santos; K. Tavangar; R. P. van der Marel; A. K. Vivas; A. R. Walker; R. H. Wechsler

doi:10.3847/1538-4357/ab6c67

Two ultra-faint Milky Way stellar systems discovered in early data from the DECam Local Volume Exploration survey

DELVE Collaboration, S. Mau, W. Cerny, A. B. Pace, Y. Choi, A. Drlica-Wagner, L. Santana-Silva, A. H. Riley, D. Erkal, G. S. Stringfellow, M. Adamów, J. L. Carlin, R. A. Gruendl, D. Hernandez-Lang, D. Hernandez-Lang, N. Kuropatkin, T. S. Li, C. E. Martínez-Vázquez, E. Morganson, B. Mutlu-PakdilE. H. Neilsen, D. L. Nidever, K. A. G. Olsen, D. J. Sand, E. J. Tollerud, D. L. Tucker, B. Yanny, A. Zenteno, S. Allam, W. A. Barkhouse, K. Bechtol, E. F. Bell, P. Balaji, D. Crnojević, J. Esteves, P. S. Ferguson, C. Gallart, A. K. Hughes, D. J. James, P. Jethwa, L. C. Johnson, K. Kuehn, S. Majewski, Y. Y. Mao, P. Massana, M. McNanna, A. Monachesi, E. O. Nadler, N. E. D. Noël, A. Palmese, F. Paz-Chinchon, A. Pieres, J. Sanchez, N. Shipp, J. D. Simon, M. Soares-Santos, K. Tavangar, R. P. van der Marel, A. K. Vivas, A. R. Walker, R. H. Wechsler

Australian Astronomical Optics

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6 Citations (Scopus)

Abstract

We report the discovery of two ultra-faint stellar systems found in early data from the DECam Local Volume Exploration survey (DELVE). The first system, Centaurus I (DELVE J1238-4054), is identified as a resolved overdensity of old and metal-poor stars with a heliocentric distance of D_⊙=116.3_-0.6^+0.6, a half-light radius of r_h = 2.3_-0.3 ^+0.4 arcmin, an age of τ > 12.85 Gyr, a metallicity of Z = 0.0002_-0.0002 ^+0.0001, and an absolute magnitude of M_V = -5.55_-0.11 ^+0.11. This characterization is consistent with the population of ultra-faint satellites and confirmation of this system would make Centaurus I one of the brightest recently discovered ultra-faint dwarf galaxies. Centaurus I is detected in Gaia DR2 with a clear and distinct proper motion signal, confirming that it is a real association of stars distinct from the Milky Way foreground; this is further supported by the clustering of blue horizontal branch stars near the centroid of the system. The second system, DELVE 1 (DELVE J1630-0058), is identified as a resolved overdensity of stars with a heliocentric distance of D_⊙ = 19.0_-0.6 ^+0.5 kpc, a half-light radius of r_h = 0.97_-0.17 ^+0.24 arcmin, an age of τ = 12.5_-0.7 ^+1.0 Gyr, a metallicity of Z = 0.0005_-0.0001 ^+0.0002, and an absolute magnitude of M_V = 0.2_-0.6 ^+0.8, consistent with the known population of faint halo star clusters. Given the low number of probable member stars at magnitudes accessible with Gaia DR2, a proper motion signal for DELVE 1 is only marginally detected. We compare the spatial position and proper motion of both Centaurus I and DELVE 1 with simulations of the accreted satellite population of the Large Magellanic Cloud (LMC) and find that neither is likely to be associated with the LMC.

Original language	English
Article number	136
Pages (from-to)	1-12
Number of pages	12
Journal	Astrophysical Journal
Volume	890
Issue number	2
DOIs	https://doi.org/10.3847/1538-4357/ab6c67
Publication status	Published - 20 Feb 2020

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10.3847/1538-4357/ab6c67

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DELVE Collaboration, Mau, S., Cerny, W., Pace, A. B., Choi, Y., Drlica-Wagner, A., Santana-Silva, L., Riley, A. H., Erkal, D., Stringfellow, G. S., Adamów, M., Carlin, J. L., Gruendl, R. A., Hernandez-Lang, D., Hernandez-Lang, D., Kuropatkin, N., Li, T. S., Martínez-Vázquez, C. E., Morganson, E., ... Wechsler, R. H. (2020). Two ultra-faint Milky Way stellar systems discovered in early data from the DECam Local Volume Exploration survey. Astrophysical Journal, 890(2), 1-12. [136]. https://doi.org/10.3847/1538-4357/ab6c67

DELVE Collaboration ; Mau, S. ; Cerny, W. ; Pace, A. B. ; Choi, Y. ; Drlica-Wagner, A. ; Santana-Silva, L. ; Riley, A. H. ; Erkal, D. ; Stringfellow, G. S. ; Adamów, M. ; Carlin, J. L. ; Gruendl, R. A. ; Hernandez-Lang, D. ; Hernandez-Lang, D. ; Kuropatkin, N. ; Li, T. S. ; Martínez-Vázquez, C. E. ; Morganson, E. ; Mutlu-Pakdil, B. ; Neilsen, E. H. ; Nidever, D. L. ; Olsen, K. A. G. ; Sand, D. J. ; Tollerud, E. J. ; Tucker, D. L. ; Yanny, B. ; Zenteno, A. ; Allam, S. ; Barkhouse, W. A. ; Bechtol, K. ; Bell, E. F. ; Balaji, P. ; Crnojević, D. ; Esteves, J. ; Ferguson, P. S. ; Gallart, C. ; Hughes, A. K. ; James, D. J. ; Jethwa, P. ; Johnson, L. C. ; Kuehn, K. ; Majewski, S. ; Mao, Y. Y. ; Massana, P. ; McNanna, M. ; Monachesi, A. ; Nadler, E. O. ; Noël, N. E. D. ; Palmese, A. ; Paz-Chinchon, F. ; Pieres, A. ; Sanchez, J. ; Shipp, N. ; Simon, J. D. ; Soares-Santos, M. ; Tavangar, K. ; van der Marel, R. P. ; Vivas, A. K. ; Walker, A. R. ; Wechsler, R. H. / Two ultra-faint Milky Way stellar systems discovered in early data from the DECam Local Volume Exploration survey. In: Astrophysical Journal. 2020 ; Vol. 890, No. 2. pp. 1-12.

@article{b6e828c06eb94425af4ce5c49be8f8b6,

title = "Two ultra-faint Milky Way stellar systems discovered in early data from the DECam Local Volume Exploration survey",

abstract = "We report the discovery of two ultra-faint stellar systems found in early data from the DECam Local Volume Exploration survey (DELVE). The first system, Centaurus I (DELVE J1238-4054), is identified as a resolved overdensity of old and metal-poor stars with a heliocentric distance of D⊙ =116.3-0.6+0.6, a half-light radius of rh = 2.3-0.3 +0.4 arcmin, an age of τ > 12.85 Gyr, a metallicity of Z = 0.0002-0.0002 +0.0001, and an absolute magnitude of MV = -5.55-0.11 +0.11. This characterization is consistent with the population of ultra-faint satellites and confirmation of this system would make Centaurus I one of the brightest recently discovered ultra-faint dwarf galaxies. Centaurus I is detected in Gaia DR2 with a clear and distinct proper motion signal, confirming that it is a real association of stars distinct from the Milky Way foreground; this is further supported by the clustering of blue horizontal branch stars near the centroid of the system. The second system, DELVE 1 (DELVE J1630-0058), is identified as a resolved overdensity of stars with a heliocentric distance of D⊙ = 19.0-0.6 +0.5 kpc, a half-light radius of rh = 0.97-0.17 +0.24 arcmin, an age of τ = 12.5-0.7 +1.0 Gyr, a metallicity of Z = 0.0005-0.0001 +0.0002, and an absolute magnitude of MV = 0.2-0.6 +0.8, consistent with the known population of faint halo star clusters. Given the low number of probable member stars at magnitudes accessible with Gaia DR2, a proper motion signal for DELVE 1 is only marginally detected. We compare the spatial position and proper motion of both Centaurus I and DELVE 1 with simulations of the accreted satellite population of the Large Magellanic Cloud (LMC) and find that neither is likely to be associated with the LMC.",

author = "{DELVE Collaboration} and S. Mau and W. Cerny and Pace, {A. B.} and Y. Choi and A. Drlica-Wagner and L. Santana-Silva and Riley, {A. H.} and D. Erkal and Stringfellow, {G. S.} and M. Adam{\'o}w and Carlin, {J. L.} and Gruendl, {R. A.} and D. Hernandez-Lang and D. Hernandez-Lang and N. Kuropatkin and Li, {T. S.} and Mart{\'i}nez-V{\'a}zquez, {C. E.} and E. Morganson and B. Mutlu-Pakdil and Neilsen, {E. H.} and Nidever, {D. L.} and Olsen, {K. A. G.} and Sand, {D. J.} and Tollerud, {E. J.} and Tucker, {D. L.} and B. Yanny and A. Zenteno and S. Allam and Barkhouse, {W. A.} and K. Bechtol and Bell, {E. F.} and P. Balaji and D. Crnojevi{\'c} and J. Esteves and Ferguson, {P. S.} and C. Gallart and Hughes, {A. K.} and James, {D. J.} and P. Jethwa and Johnson, {L. C.} and K. Kuehn and S. Majewski and Mao, {Y. Y.} and P. Massana and M. McNanna and A. Monachesi and Nadler, {E. O.} and No{\"e}l, {N. E. D.} and A. Palmese and F. Paz-Chinchon and A. Pieres and J. Sanchez and N. Shipp and Simon, {J. D.} and M. Soares-Santos and K. Tavangar and {van der Marel}, {R. P.} and Vivas, {A. K.} and Walker, {A. R.} and Wechsler, {R. H.}",

year = "2020",

month = feb,

day = "20",

doi = "10.3847/1538-4357/ab6c67",

language = "English",

volume = "890",

pages = "1--12",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "IOP Publishing",

number = "2",

}

DELVE Collaboration, Mau, S, Cerny, W, Pace, AB, Choi, Y, Drlica-Wagner, A, Santana-Silva, L, Riley, AH, Erkal, D, Stringfellow, GS, Adamów, M, Carlin, JL, Gruendl, RA, Hernandez-Lang, D, Hernandez-Lang, D, Kuropatkin, N, Li, TS, Martínez-Vázquez, CE, Morganson, E, Mutlu-Pakdil, B, Neilsen, EH, Nidever, DL, Olsen, KAG, Sand, DJ, Tollerud, EJ, Tucker, DL, Yanny, B, Zenteno, A, Allam, S, Barkhouse, WA, Bechtol, K, Bell, EF, Balaji, P, Crnojević, D, Esteves, J, Ferguson, PS, Gallart, C, Hughes, AK, James, DJ, Jethwa, P, Johnson, LC, Kuehn, K, Majewski, S, Mao, YY, Massana, P, McNanna, M, Monachesi, A, Nadler, EO, Noël, NED, Palmese, A, Paz-Chinchon, F, Pieres, A, Sanchez, J, Shipp, N, Simon, JD, Soares-Santos, M, Tavangar, K, van der Marel, RP, Vivas, AK, Walker, AR & Wechsler, RH 2020, 'Two ultra-faint Milky Way stellar systems discovered in early data from the DECam Local Volume Exploration survey', Astrophysical Journal, vol. 890, no. 2, 136, pp. 1-12. https://doi.org/10.3847/1538-4357/ab6c67

Two ultra-faint Milky Way stellar systems discovered in early data from the DECam Local Volume Exploration survey. / DELVE Collaboration; Mau, S.; Cerny, W.; Pace, A. B.; Choi, Y.; Drlica-Wagner, A.; Santana-Silva, L.; Riley, A. H.; Erkal, D.; Stringfellow, G. S.; Adamów, M.; Carlin, J. L.; Gruendl, R. A.; Hernandez-Lang, D.; Hernandez-Lang, D.; Kuropatkin, N.; Li, T. S.; Martínez-Vázquez, C. E.; Morganson, E.; Mutlu-Pakdil, B.; Neilsen, E. H.; Nidever, D. L.; Olsen, K. A. G.; Sand, D. J.; Tollerud, E. J.; Tucker, D. L.; Yanny, B.; Zenteno, A.; Allam, S.; Barkhouse, W. A.; Bechtol, K.; Bell, E. F.; Balaji, P.; Crnojević, D.; Esteves, J.; Ferguson, P. S.; Gallart, C.; Hughes, A. K.; James, D. J.; Jethwa, P.; Johnson, L. C.; Kuehn, K.; Majewski, S.; Mao, Y. Y.; Massana, P.; McNanna, M.; Monachesi, A.; Nadler, E. O.; Noël, N. E. D.; Palmese, A.; Paz-Chinchon, F.; Pieres, A.; Sanchez, J.; Shipp, N.; Simon, J. D.; Soares-Santos, M.; Tavangar, K.; van der Marel, R. P.; Vivas, A. K.; Walker, A. R.; Wechsler, R. H.

In: Astrophysical Journal, Vol. 890, No. 2, 136, 20.02.2020, p. 1-12.

Research output: Contribution to journal › Article › peer-review

TY - JOUR

T1 - Two ultra-faint Milky Way stellar systems discovered in early data from the DECam Local Volume Exploration survey

AU - DELVE Collaboration

AU - Mau, S.

AU - Cerny, W.

AU - Pace, A. B.

AU - Choi, Y.

AU - Drlica-Wagner, A.

AU - Santana-Silva, L.

AU - Riley, A. H.

AU - Erkal, D.

AU - Stringfellow, G. S.

AU - Adamów, M.

AU - Carlin, J. L.

AU - Gruendl, R. A.

AU - Hernandez-Lang, D.

AU - Kuropatkin, N.

AU - Li, T. S.

AU - Martínez-Vázquez, C. E.

AU - Morganson, E.

AU - Mutlu-Pakdil, B.

AU - Neilsen, E. H.

AU - Nidever, D. L.

AU - Olsen, K. A. G.

AU - Sand, D. J.

AU - Tollerud, E. J.

AU - Tucker, D. L.

AU - Yanny, B.

AU - Zenteno, A.

AU - Allam, S.

AU - Barkhouse, W. A.

AU - Bechtol, K.

AU - Bell, E. F.

AU - Balaji, P.

AU - Crnojević, D.

AU - Esteves, J.

AU - Ferguson, P. S.

AU - Gallart, C.

AU - Hughes, A. K.

AU - James, D. J.

AU - Jethwa, P.

AU - Johnson, L. C.

AU - Kuehn, K.

AU - Majewski, S.

AU - Mao, Y. Y.

AU - Massana, P.

AU - McNanna, M.

AU - Monachesi, A.

AU - Nadler, E. O.

AU - Noël, N. E. D.

AU - Palmese, A.

AU - Paz-Chinchon, F.

AU - Pieres, A.

AU - Sanchez, J.

AU - Shipp, N.

AU - Simon, J. D.

AU - Soares-Santos, M.

AU - Tavangar, K.

AU - van der Marel, R. P.

AU - Vivas, A. K.

AU - Walker, A. R.

AU - Wechsler, R. H.

PY - 2020/2/20

Y1 - 2020/2/20

N2 - We report the discovery of two ultra-faint stellar systems found in early data from the DECam Local Volume Exploration survey (DELVE). The first system, Centaurus I (DELVE J1238-4054), is identified as a resolved overdensity of old and metal-poor stars with a heliocentric distance of D⊙ =116.3-0.6+0.6, a half-light radius of rh = 2.3-0.3 +0.4 arcmin, an age of τ > 12.85 Gyr, a metallicity of Z = 0.0002-0.0002 +0.0001, and an absolute magnitude of MV = -5.55-0.11 +0.11. This characterization is consistent with the population of ultra-faint satellites and confirmation of this system would make Centaurus I one of the brightest recently discovered ultra-faint dwarf galaxies. Centaurus I is detected in Gaia DR2 with a clear and distinct proper motion signal, confirming that it is a real association of stars distinct from the Milky Way foreground; this is further supported by the clustering of blue horizontal branch stars near the centroid of the system. The second system, DELVE 1 (DELVE J1630-0058), is identified as a resolved overdensity of stars with a heliocentric distance of D⊙ = 19.0-0.6 +0.5 kpc, a half-light radius of rh = 0.97-0.17 +0.24 arcmin, an age of τ = 12.5-0.7 +1.0 Gyr, a metallicity of Z = 0.0005-0.0001 +0.0002, and an absolute magnitude of MV = 0.2-0.6 +0.8, consistent with the known population of faint halo star clusters. Given the low number of probable member stars at magnitudes accessible with Gaia DR2, a proper motion signal for DELVE 1 is only marginally detected. We compare the spatial position and proper motion of both Centaurus I and DELVE 1 with simulations of the accreted satellite population of the Large Magellanic Cloud (LMC) and find that neither is likely to be associated with the LMC.

AB - We report the discovery of two ultra-faint stellar systems found in early data from the DECam Local Volume Exploration survey (DELVE). The first system, Centaurus I (DELVE J1238-4054), is identified as a resolved overdensity of old and metal-poor stars with a heliocentric distance of D⊙ =116.3-0.6+0.6, a half-light radius of rh = 2.3-0.3 +0.4 arcmin, an age of τ > 12.85 Gyr, a metallicity of Z = 0.0002-0.0002 +0.0001, and an absolute magnitude of MV = -5.55-0.11 +0.11. This characterization is consistent with the population of ultra-faint satellites and confirmation of this system would make Centaurus I one of the brightest recently discovered ultra-faint dwarf galaxies. Centaurus I is detected in Gaia DR2 with a clear and distinct proper motion signal, confirming that it is a real association of stars distinct from the Milky Way foreground; this is further supported by the clustering of blue horizontal branch stars near the centroid of the system. The second system, DELVE 1 (DELVE J1630-0058), is identified as a resolved overdensity of stars with a heliocentric distance of D⊙ = 19.0-0.6 +0.5 kpc, a half-light radius of rh = 0.97-0.17 +0.24 arcmin, an age of τ = 12.5-0.7 +1.0 Gyr, a metallicity of Z = 0.0005-0.0001 +0.0002, and an absolute magnitude of MV = 0.2-0.6 +0.8, consistent with the known population of faint halo star clusters. Given the low number of probable member stars at magnitudes accessible with Gaia DR2, a proper motion signal for DELVE 1 is only marginally detected. We compare the spatial position and proper motion of both Centaurus I and DELVE 1 with simulations of the accreted satellite population of the Large Magellanic Cloud (LMC) and find that neither is likely to be associated with the LMC.

UR - http://www.scopus.com/inward/record.url?scp=85081672682&partnerID=8YFLogxK

U2 - 10.3847/1538-4357/ab6c67

DO - 10.3847/1538-4357/ab6c67

M3 - Article

AN - SCOPUS:85081672682

VL - 890

SP - 1

EP - 12

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

M1 - 136

ER -

Two ultra-faint Milky Way stellar systems discovered in early data from the DECam Local Volume Exploration survey

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