A Caltech Library Service

Mapping the Northern Galactic Disk Warp with Classical Cepheids

Skowron, D. M. and Skowron, J. and Mróz, P. and Udalski, A. and Pietrukowicz, P. and Soszyński, I. and Szymański, M. K. and Poleski, R. and Kozłowski, S. and Ulaczyk, K. and Rybicki, K. and Iwanek, P. and Wrona, M. and Gromadzki, M. (2019) Mapping the Northern Galactic Disk Warp with Classical Cepheids. Acta Astronomica, 69 (4). pp. 305-320. ISSN 0001-5237.

[img] PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


We present an updated three dimensional map of the Milky Way based on a sample of 2431 classical Cepheid variable stars, supplemented with about 200 newly detected classical Cepheids from the OGLE survey. The new objects were discovered as a result of a dedicated observing campaign of the ≈280 square degree extension of the OGLE footprint of the Galactic disk during 2018-2019 observing seasons. These regions cover the main part of the northern Galactic warp that has been deficient in Cepheids so far. We use direct distances to the sample of over 2390 classical Cepheids to model the distribution of the young stellar population in the Milky Way and recalculate the parameters of the Galactic disk warp. Our data show that its northern part is very prominent and its amplitude is ≈10% larger than that of the southern part. By combining Gaia astrometric data with the Galactic rotation curve and distances to Cepheids from our sample, we construct a map of the vertical component of the velocity vector for all Cepheids in the Milky Way disk. We find large-scale vertical motions with amplitudes of 10-20 km/s, such that Cepheids located in the northern warp exhibit large positive vertical velocity (toward the north Galactic pole), whereas those in the southern warp - negative vertical velocity (toward the south Galactic pole).

Item Type:Article
Related URLs:
URLURL TypeDescription
Skowron, J.0000-0002-2335-1730
Mróz, P.0000-0001-7016-1692
Udalski, A.0000-0001-5207-5619
Pietrukowicz, P.0000-0002-2339-5899
Poleski, R.0000-0002-9245-6368
Ulaczyk, K.0000-0001-6364-408X
Iwanek, P.0000-0002-6212-7221
Gromadzki, M.0000-0002-1650-1518
Additional Information:© 2019 Copernicus Foundation for Polish Astronomy. Received November 29, 2019. The OGLE project has received funding from the National Science Center (NCN) grant MAESTRO 2014/14/A/ST9/00121 to AU. This work has been supported in part by the NCN grant MAESTRO 2016/22/A/ST9/00009 to IS. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. 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.
Funding AgencyGrant Number
National Science Centre (Poland)MAESTRO 2014/14/A/ST9/00121
National Science Centre (Poland)MAESTRO 2016/22/A/ST9/00009
Gaia Multilateral AgreementUNSPECIFIED
Subject Keywords:Galaxy: structure – Galaxy: kinematics and dynamics – Galaxy: stellar content – Stars: oscillations
Issue or Number:4
Record Number:CaltechAUTHORS:20200220-141641327
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:101429
Deposited By: Tony Diaz
Deposited On:20 Feb 2020 22:29
Last Modified:09 Mar 2020 13:19

Repository Staff Only: item control page