J/AJ/170/294 DELVE DR2: Jacobi radii for 159 globular clusters (Chiti+, 2025)
DELVE-ing into the Milky Way's globular clusters: Assessing extratidal features
in NGC 5897, NGC 7492, and testing detectability with deeper photometry.
Chiti A., Tavangar K., Ferguson P.S., Carballo-Bello J.A., Senkevich A.M.,
Erkal D., Drlica-Wagner A., Pace A.B., Ji A.P., Sand D.J., Limberg G.,
Chaturvedi A., Crnojevic D., Medina G.E., Riley A.H., Shipp N.,
Vivas A.K., Wertheim M., Choi Y., Martinez-Vazquez C.E., Mutlu-Pakdil B.,
Navabi M., Sakowska J.D., Stringfellow G.S., Zenteno A.,
DELVE Collaboration
<Astron. J., 170, 294 (2025)>
=2025AJ....170..294C 2025AJ....170..294C
ADC_Keywords: Clusters, globular; Milky Way; Photometry, ugriz; Models
Keywords: Globular star clusters ; Milky Way Galaxy ; Tidal disruption
Abstract:
Extratidal features around globular clusters (GCs) are tracers of
their disruption, stellar stream formation, and their host's
gravitational potential. However, these features remain challenging to
detect due to their low surface brightness. We conduct a systematic
search for such features around 19 GCs in the DECam Local Volume
Exploration (DELVE) survey Data Release 2, discovering a new
extra-tidal envelope around NGC 5897 and find tentative evidence for
an extended envelope surrounding NGC 7492. Through a combination of
dynamical modeling and analyzing synthetic stellar populations, we
demonstrate these envelopes may have formed through tidal disruption.
We use these models to explore the detectability of these features in
the upcoming Legacy Survey of Space and Time (LSST), finding that
while LSST's deeper photometry will enhance detection significance,
additional methods for foreground removal like proper motions or
metallicities may be important for robust stream detection. Our
results both add to the sample of globular clusters with extratidal
features and provide insights on interpreting similar features in
current and upcoming data.
Description:
The DECam Local Volume Exploration (DELVE) survey Data Release 2
provides coverage of ∼21,000deg2 of the high-latitude (|b|>10°)
sky in the broadband DECam g, r, i, z filters.
DELVE aims to combine archival Dark Energy Camera (DECam) observations
with more than 150 nights of new data for contiguous coverage of the
high-latitude southern sky. DELVE DR2 includes >160,000 exposures from
a variety of NOIRLab community programs, with the largest number of
exposures from DELVE (Drlica-Wagner+2021ApJS..256....2D),
DES (Abbott+2021, II/371), DECaLS (Dey+2019AJ....157..168D), and the
DECam eROSITA Survey (DeROSITAS; Zenteno+2025A&A...698A.171Z).
We supplemented our photometric data set with astrometric data from
Gaia DR3 (I/355) at the bright end of our catalog (g≤20.5). We
retrieved isochrones from the MESA Isochrones and Stellar Tracks
(MIST) library (Paxton+2010ascl.soft10083P).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 47 159 A compilation of the Jacobi radii for 159 globular
clusters (used in Figures 10 and 11)
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
II/371 : The Dark Energy Survey (DES): Data Release 2 (Abbott+, 2021)
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
II/388 : Euclid final merged catalog. Q1 data release (Euclid Coll., 2025)
VII/195 : Globular Clusters in the Milky Way (Harris, 1996)
VII/202 : Globular Clusters in the Milky Way (Harris, 1997)
J/ApJ/684/1143 : BHB candidates in the Milky Way (Xue+, 2008)
J/ApJ/757/83 : The Blanco Cosmology Survey (BCS) (Desai+, 2012)
J/A+A/565/A23 : Abundances of NGC5897 red giants (Koch+, 2014)
J/MNRAS/474/2479 : Orbital parameters of globular clusters (Balbinot+, 2018)
J/MNRAS/478/1520 : Milky Way globular clusters data (Baumgardt+, 2018)
J/ApJ/857/144 : Tidal features from RESOLVE surv. & DECaLS images (Hood+, 2018)
J/ApJ/860/65 : MegaCam survey of outer halo satellites. I. (Munoz+, 2018)
J/MNRAS/482/5138 : Galactic GC mean pm & velocities (Baumgardt+, 2019)
J/MNRAS/485/4906 : GC number density profiles using Gaia DR2 (de Boer+, 2019)
J/MNRAS/485/4726 : An all-sky view of the Orphan Stream (Koposov+, 2019)
J/MNRAS/490/3508 : The Southern Stellar Stream Sp. Survey (S5) (Li+, 2019)
J/MNRAS/489/4367 : Radii of the Milky Way globular clusters (Piatti+, 2019)
J/ApJ/885/3 : Membership in 12 stellar streams from DES (Shipp+, 2019)
J/MNRAS/484/2832 : Proper motions of Milky Way globular clust. (Vasiliev, 2019)
J/ApJS/240/5 : SHELA. II. DECam and IRAC multiwavelength catalog (Wold+, 2019)
J/ApJ/893/47 : Milky Way satellite census. I. DES & PS1 (Drlica-Wagner+, 2020)
J/ApJ/914/123 : Gaia DR2 and EDR3 stars with sp. follow-up (Ibata+, 2021)
J/MNRAS/505/5978 : Gaia EDR3 view on Galactic globular clust. (Vasiliev+, 2021)
J/MNRAS/501/2279 : Stars in the Sagittarius stream (Vasiliev+, 2021)
J/AJ/163/18 : Thin stell. stream on retrograde orbit at 30kpc (Ferguson+, 2022)
J/A+A/665/A8 : Extra-tidal star candidates in Sgr dSph Galaxy (Kundu+, 2022)
J/A+A/666/A64 : Sagittarius stream with eDR3 (Ramos+, 2022)
J/MNRAS/518/4249 : Study of extra-tidal M3 stars: APOGEE/Gaia (Grondin+, 2023)
J/AJ/167/135 : The DECam Ecliptic Exploration Proj (DEEP). IV. (Strauss+, 2024)
J/A+A/693/A69 : NGC 1261 and NGC 1904 potential members (Awad+, 2025)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name Globular Cluster identifier
16- 20 F5.1 pc rJperi [1.9/187.2] Jacobi radius at pericenter (1)
22- 25 F4.1 pc e_rJperi [0.1/71] Lower one sigma uncertainty in rJperi
27- 31 F5.1 pc E_rJperi [0.2/122.5] Upper one sigma uncertainty in
rJperi
33- 37 F5.1 pc rJapo [16/836.9] Jacobi radius at apocenter (1)
39- 42 F4.1 pc e_rJapo [0.3/47.1] Lower one sigma uncertainty in rJapo
44- 47 F4.1 pc E_rJapo [0.4/79.3] Upper one sigma uncertainty in rJapo
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Note (1): The Jacobi radius rJ is from King+1962AJ.....67..471K:
rJ = ( GmGC / (ω2 - (d2 Φ_{G}(R) / dR2)|R(GC) )1/3
where ω is the angular velocity, mGC is the mass of the GC,
R(GC) is the distance of the GC from the Galactic center, and ΦG
is the Milky Way potential (See Equation 1).
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History:
From electronic version of the journal
License: CC-BY-4.0
(End) Prepared by [AAS], Robin Leichtnam [CDS] 25-Aug-2026