Cold Dark Matter Substructure and Galactic Disks I: Morphological Signatures of Hierarchical SatelliteAccretion

PDF Version Also Available for Download.

Description

We conduct a series of high-resolution, fully self-consistent dissipation less N-body simulations to investigate the cumulative effect of substructure mergers onto thin disk galaxies in the context of the {Lambda}CDM paradigm of structure formation. Our simulation campaign is based on a hybrid approach combining cosmological simulations and controlled numerical experiments. Substructure mass functions, orbital distributions, internal structures, and accretion times are culled directly from cosmological simulations of galaxy-sized cold dark matter (CDM) halos. We demonstrate that accretions of massive subhalos onto the central regions of host halos, where the galactic disk resides, since z {approx} 1 should be common occurrences. ... continued below

Physical Description

20 pages

Creation Information

Kazantzidis, Stelios; Bullock, James S.; Zentner, Andrew R.; Kravtsov, Andrey V. & Moustakas, Leonidas A. December 3, 2007.

Context

This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this article can be viewed below.

Who

People and organizations associated with either the creation of this article or its content.

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this article. Follow the links below to find similar items on the Digital Library.

Description

We conduct a series of high-resolution, fully self-consistent dissipation less N-body simulations to investigate the cumulative effect of substructure mergers onto thin disk galaxies in the context of the {Lambda}CDM paradigm of structure formation. Our simulation campaign is based on a hybrid approach combining cosmological simulations and controlled numerical experiments. Substructure mass functions, orbital distributions, internal structures, and accretion times are culled directly from cosmological simulations of galaxy-sized cold dark matter (CDM) halos. We demonstrate that accretions of massive subhalos onto the central regions of host halos, where the galactic disk resides, since z {approx} 1 should be common occurrences. In contrast, extremely few satellites in present-day CDM halos are likely to have a significant impact on the disk structure. This is due to the fact that massive subhalos with small orbital pericenters that are most capable of strongly perturbing the disk become either tidally disrupted or suffer substantial mass loss prior to z = 0. One host halo merger history is subsequently used to seed controlled N-body experiments of repeated satellite impacts on an initially-thin Milky Way-type disk galaxy. These simulations track the effects of six dark matter substructures, with initial masses in the range {approx} (0.7-2) x 10{sup 10} M{sub {circle_dot}} ({approx} 20-60% of the disk mass), crossing the disk in the past {approx} 8 Gyr. We show that these accretion events produce several distinctive observational signatures in the stellar disk including: a long-lived, low-surface brightness, ring-like feature in the outskirts; a significant flare; a central bar; and faint filamentary structures that (spuriously) resemble tidal streams in configuration space. The final distribution of disk stars exhibits a complex vertical structure that is well-described by a standard 'thin-thick' disk decomposition, where the 'thick' disk component has emerged primarily as a result of the interaction with the most massive subhalo. We conclude that satellite-disk encounters of the kind expected in {Lambda}CDM models can induce morphological features in galactic disks that are similar to those being discovered in the Milky Way, M31, and in other nearby and distant disk galaxies. These results highlight the significant role of CDM substructure in setting the structure of disk galaxies and driving galaxy evolution. Upcoming galactic structure surveys and astrometric satellites may be able to distinguish between competing cosmological models by testing whether the detailed structure of galactic disks is as excited as predicted by the CDM paradigm.

Physical Description

20 pages

Source

  • Journal Name: Astrophysical Journal

Language

Item Type

Identifier

Unique identifying numbers for this article in the Digital Library or other systems.

  • Report No.: SLAC-PUB-13027
  • Grant Number: AC02-76SF00515
  • Office of Scientific & Technical Information Report Number: 920598
  • Archival Resource Key: ark:/67531/metadc902123

Collections

This article is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this article?

When

Dates and time periods associated with this article.

Creation Date

  • December 3, 2007

Added to The UNT Digital Library

  • Sept. 27, 2016, 1:39 a.m.

Description Last Updated

  • Nov. 22, 2016, 10:46 p.m.

Usage Statistics

When was this article last used?

Congratulations! It looks like you are the first person to view this item online.

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Kazantzidis, Stelios; Bullock, James S.; Zentner, Andrew R.; Kravtsov, Andrey V. & Moustakas, Leonidas A. Cold Dark Matter Substructure and Galactic Disks I: Morphological Signatures of Hierarchical SatelliteAccretion, article, December 3, 2007; [Menlo Park, California]. (digital.library.unt.edu/ark:/67531/metadc902123/: accessed December 11, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.