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The Extended Tidal Tails of NGC 7089 (M2)

Grillmair, Carl J. (2022) The Extended Tidal Tails of NGC 7089 (M2). Astrophysical Journal, 929 (1). Art. No. 89. ISSN 0004-637X. doi:10.3847/1538-4357/ac5bd7.

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Using photometry and proper motions from Gaia Early Data Release 3, we detect a 45° long trailing stellar debris stream associated with the old, metal-poor globular cluster NGC 7089. With a width on the order of 100 pc, the extended stream appears to be as dynamically cold as the coldest known streams found to date. There is some evidence for an extended leading tail extending between 28° and 37° from the cluster, though the greater distance of this tail, combined with proper motions that are virtually indistinguishable from those of foreground stars, make the detection much less certain. The proper motion profile and the path on the sky of the trailing tail are not well matched using a simple Galactic potential composed purely of a disk, bulge, and spherical halo. However, the addition of a moving, massive (M = 1.88 × 10¹¹ M⊙) Large Magellanic Cloud brings the model predictions into much better agreement with the observables. We provide tables of the most highly ranked candidate stream stars for follow-up by ongoing and future spectroscopic surveys.

Item Type:Article
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URLURL TypeDescription Paper
Grillmair, Carl J.0000-0003-4072-169X
Additional Information:© 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2022 January 20; revised 2022 March 5; accepted 2022 March 7; published 2022 April 15. We are very grateful to Rodrigo Ibata for kindly providing the table of positions and proper motions for the NGC 7089 stream stars detected in Ibata et al. (2021). We are also grateful to an anonymous referee whose careful reading of the manuscript significantly improved the final product. This work has made use of data from the European Space Agency (ESA) mission Gaia (, processed by the Gaia Data Processing and Analysis Consortium (DPAC; Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. Facilities: Gaia - , SDSS - , LaMost - .
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Gaia Multilateral AgreementUNSPECIFIED
Subject Keywords:Stellar streams; Galaxy structure
Issue or Number:1
Classification Code:Unified Astronomy Thesaurus concepts: Stellar streams (2166); Galaxy structure (622)
Record Number:CaltechAUTHORS:20220511-346539200
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Official Citation:Carl J. Grillmair 2022 ApJ 929 89
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:114689
Deposited By: Tony Diaz
Deposited On:11 May 2022 23:55
Last Modified:11 May 2022 23:55

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