Asset Details
Do you wish to reserve the book?
A tidally distorted dwarf galaxy near NGC 4449
Hey, we have placed the reservation for you!
By the way, why not check out events that you can attend while you pick your title.
Oops! Something went wrong.
Looks like we were not able to place the reservation. Kindly try again later.
Are you sure you want to remove the book from the shelf?
A tidally distorted dwarf galaxy near NGC 4449
Do you wish to request the book?
A tidally distorted dwarf galaxy near NGC 4449
Please be aware that the book you have requested cannot be checked out. If you would like to checkout this book, you can reserve another copy
We have requested the book for you!
Your request is successful and it will be processed during the Library working hours. Please check the status of your request in My Requests.
Oops! Something went wrong.
Looks like we were not able to place your request. Kindly try again later.
Journal Article
A tidally distorted dwarf galaxy near NGC 4449
2012
Overview
A dwarf galaxy companion to NGC 4449 is reported, and is found to be in a transient stage of tidal disruption.
Aftermath of an intergalactic collision
The nearby starburst galaxy NGC 4449 is surrounded by a neutral HI cloud complex with a variety of features including rings, shells and a counter-rotating core. This complexity is suggestive of interactions with another galaxy, possibly the dwarf irregular galaxy DDO 125, at a distance of 40 kiloparsecs. But new observations of the region around NGC 4449 reveal a previously unknown companion, a tidally distorted smaller galaxy, named NGC 4449B. Its properties, such as its S-shaped morphology (resembling the Sagittarius dwarf near the Milky Way), suggest that it has had a close encounter with NGC 4449.
NGC 4449 is a nearby Magellanic irregular starburst galaxy
1
with a B-band absolute magnitude of −18 and a prominent, massive, intermediate-age nucleus
2
at a distance from Earth of 3.8 megaparsecs (ref.
3
). It is wreathed in an extraordinary neutral hydrogen (H
i
) complex, which includes rings, shells and a counter-rotating core, spanning ∼90 kiloparsecs (kpc; refs
1
,
4
). NGC 4449 is relatively isolated
5
, although an interaction with its nearest known companion—the galaxy DDO 125, some 40 kpc to the south—has been proposed as being responsible for the complexity of its H
i
structure
6
. Here we report the presence of a dwarf galaxy companion to NGC 4449, namely NGC 4449B. This companion has a V-band absolute magnitude of −13.4 and a half-light radius of 2.7 kpc, with a full extent of around 8 kpc. It is in a transient stage of tidal disruption, similar to that of the Sagittarius dwarf
7
near the Milky Way. NGC 4449B exhibits a striking S-shaped morphology that has been predicted for disrupting galaxies
7
,
8
but has hitherto been seen only in a dissolving globular cluster
9
. We also detect an additional arc or disk ripple embedded in a two-component stellar halo, including a component extending twice as far as previously known, to about 20 kpc from the galaxy’s centre.
Publisher
Nature Publishing Group UK,Nature Publishing Group
Subject
/ Disks
/ Dwarf galaxies (elliptical, irregular, and spheroidal)
/ Exact sciences and technology
/ Halos
/ Humanities and Social Sciences
/ Irregular and morphologically peculiar galaxies
/ letter
/ Local group. Magellanic clouds
/ Normal galaxies. Extragalactic objects and systems (by type)
/ Ripples
/ Science
/ Shells
/ Stellar systems. Galactic and extragalactic objects and systems. The universe
