Accretion-inhibited star formation in the warm molecular disk of the green-valley elliptical galaxy NGC 3226?

P. N. Appleton, C. Mundell, T. Bitsakis, M. Lacy, K. Alatalo, L. Armus, V. Charmandaris, P.-a. Duc, U. Lisenfeld, P. Ogle

Research output: Contribution to journalArticle

11 Citations (Scopus)
75 Downloads (Pure)

Abstract

We present archival Spitzer photometry and spectroscopy and Herschel photometry of the peculiar "Green Valley" elliptical galaxy NGC 3226. The galaxy, which contains a low-luminosity active galactic nucleus (AGN), forms a pair with NGC 3227 and is shown to lie in a complex web of stellar and H I filaments. Imaging at 8 and 16 μm reveals a curved plume structure 3 kpc in extent, embedded within the core of the galaxy and coincident with the termination of a 30 kpc long H I tail. In situ star formation associated with the infrared (IR) plume is identified from narrowband Hubble Space Telescope (HST) imaging. The end of the IR plume coincides with a warm molecular hydrogen disk and dusty ring containing 0.7-1.1 × 107 M ☉ detected within the central kiloparsec. Sensitive upper limits to the detection of cold molecular gas may indicate that a large fraction of the H2 is in a warm state. Photometry derived from the ultraviolet (UV) to the far-IR shows evidence for a low star-formation rate of ~0.04 M ☉ yr–1 averaged over the last 100 Myr. A mid-IR component to the spectral energy distribution (SED) contributes ~20% of the IR luminosity of the galaxy, and is consistent with emission associated with the AGN. The current measured star formation rate is insufficient to explain NGC 3226's global UV-optical "green" colors via the resurgence of star formation in a "red and dead" galaxy. This form of "cold accretion" from a tidal stream would appear to be an inefficient way to rejuvenate early-type galaxies and may actually inhibit star formation.
Original languageEnglish
Pages (from-to)117
JournalAstrophysical Journal
Volume797
Issue number2
Early online date5 Dec 2014
DOIs
Publication statusPublished - 20 Dec 2014

Fingerprint

elliptical galaxies
valleys
star formation
plume
accretion
galaxies
valley
plumes
photometry
star formation rate
active galactic nuclei
luminosity
spectroscopy
hydrogen
cold gas
molecular gases
spectral energy distribution
Hubble Space Telescope
narrowband
filaments

Cite this

Accretion-inhibited star formation in the warm molecular disk of the green-valley elliptical galaxy NGC 3226? / Appleton, P. N.; Mundell, C.; Bitsakis, T.; Lacy, M.; Alatalo, K.; Armus, L.; Charmandaris, V.; Duc, P.-a.; Lisenfeld, U.; Ogle, P.

In: Astrophysical Journal, Vol. 797, No. 2, 20.12.2014, p. 117.

Research output: Contribution to journalArticle

Appleton, PN, Mundell, C, Bitsakis, T, Lacy, M, Alatalo, K, Armus, L, Charmandaris, V, Duc, P, Lisenfeld, U & Ogle, P 2014, 'Accretion-inhibited star formation in the warm molecular disk of the green-valley elliptical galaxy NGC 3226?', Astrophysical Journal, vol. 797, no. 2, pp. 117. https://doi.org/10.1088/0004-637X/797/2/117
Appleton, P. N. ; Mundell, C. ; Bitsakis, T. ; Lacy, M. ; Alatalo, K. ; Armus, L. ; Charmandaris, V. ; Duc, P.-a. ; Lisenfeld, U. ; Ogle, P. / Accretion-inhibited star formation in the warm molecular disk of the green-valley elliptical galaxy NGC 3226?. In: Astrophysical Journal. 2014 ; Vol. 797, No. 2. pp. 117.
@article{3ab346e6405741a5bed1416fa6aceb12,
title = "Accretion-inhibited star formation in the warm molecular disk of the green-valley elliptical galaxy NGC 3226?",
abstract = "We present archival Spitzer photometry and spectroscopy and Herschel photometry of the peculiar {"}Green Valley{"} elliptical galaxy NGC 3226. The galaxy, which contains a low-luminosity active galactic nucleus (AGN), forms a pair with NGC 3227 and is shown to lie in a complex web of stellar and H I filaments. Imaging at 8 and 16 μm reveals a curved plume structure 3 kpc in extent, embedded within the core of the galaxy and coincident with the termination of a 30 kpc long H I tail. In situ star formation associated with the infrared (IR) plume is identified from narrowband Hubble Space Telescope (HST) imaging. The end of the IR plume coincides with a warm molecular hydrogen disk and dusty ring containing 0.7-1.1 × 107 M ☉ detected within the central kiloparsec. Sensitive upper limits to the detection of cold molecular gas may indicate that a large fraction of the H2 is in a warm state. Photometry derived from the ultraviolet (UV) to the far-IR shows evidence for a low star-formation rate of ~0.04 M ☉ yr–1 averaged over the last 100 Myr. A mid-IR component to the spectral energy distribution (SED) contributes ~20{\%} of the IR luminosity of the galaxy, and is consistent with emission associated with the AGN. The current measured star formation rate is insufficient to explain NGC 3226's global UV-optical {"}green{"} colors via the resurgence of star formation in a {"}red and dead{"} galaxy. This form of {"}cold accretion{"} from a tidal stream would appear to be an inefficient way to rejuvenate early-type galaxies and may actually inhibit star formation.",
author = "Appleton, {P. N.} and C. Mundell and T. Bitsakis and M. Lacy and K. Alatalo and L. Armus and V. Charmandaris and P.-a. Duc and U. Lisenfeld and P. Ogle",
year = "2014",
month = "12",
day = "20",
doi = "10.1088/0004-637X/797/2/117",
language = "English",
volume = "797",
pages = "117",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing",
number = "2",

}

TY - JOUR

T1 - Accretion-inhibited star formation in the warm molecular disk of the green-valley elliptical galaxy NGC 3226?

AU - Appleton, P. N.

AU - Mundell, C.

AU - Bitsakis, T.

AU - Lacy, M.

AU - Alatalo, K.

AU - Armus, L.

AU - Charmandaris, V.

AU - Duc, P.-a.

AU - Lisenfeld, U.

AU - Ogle, P.

PY - 2014/12/20

Y1 - 2014/12/20

N2 - We present archival Spitzer photometry and spectroscopy and Herschel photometry of the peculiar "Green Valley" elliptical galaxy NGC 3226. The galaxy, which contains a low-luminosity active galactic nucleus (AGN), forms a pair with NGC 3227 and is shown to lie in a complex web of stellar and H I filaments. Imaging at 8 and 16 μm reveals a curved plume structure 3 kpc in extent, embedded within the core of the galaxy and coincident with the termination of a 30 kpc long H I tail. In situ star formation associated with the infrared (IR) plume is identified from narrowband Hubble Space Telescope (HST) imaging. The end of the IR plume coincides with a warm molecular hydrogen disk and dusty ring containing 0.7-1.1 × 107 M ☉ detected within the central kiloparsec. Sensitive upper limits to the detection of cold molecular gas may indicate that a large fraction of the H2 is in a warm state. Photometry derived from the ultraviolet (UV) to the far-IR shows evidence for a low star-formation rate of ~0.04 M ☉ yr–1 averaged over the last 100 Myr. A mid-IR component to the spectral energy distribution (SED) contributes ~20% of the IR luminosity of the galaxy, and is consistent with emission associated with the AGN. The current measured star formation rate is insufficient to explain NGC 3226's global UV-optical "green" colors via the resurgence of star formation in a "red and dead" galaxy. This form of "cold accretion" from a tidal stream would appear to be an inefficient way to rejuvenate early-type galaxies and may actually inhibit star formation.

AB - We present archival Spitzer photometry and spectroscopy and Herschel photometry of the peculiar "Green Valley" elliptical galaxy NGC 3226. The galaxy, which contains a low-luminosity active galactic nucleus (AGN), forms a pair with NGC 3227 and is shown to lie in a complex web of stellar and H I filaments. Imaging at 8 and 16 μm reveals a curved plume structure 3 kpc in extent, embedded within the core of the galaxy and coincident with the termination of a 30 kpc long H I tail. In situ star formation associated with the infrared (IR) plume is identified from narrowband Hubble Space Telescope (HST) imaging. The end of the IR plume coincides with a warm molecular hydrogen disk and dusty ring containing 0.7-1.1 × 107 M ☉ detected within the central kiloparsec. Sensitive upper limits to the detection of cold molecular gas may indicate that a large fraction of the H2 is in a warm state. Photometry derived from the ultraviolet (UV) to the far-IR shows evidence for a low star-formation rate of ~0.04 M ☉ yr–1 averaged over the last 100 Myr. A mid-IR component to the spectral energy distribution (SED) contributes ~20% of the IR luminosity of the galaxy, and is consistent with emission associated with the AGN. The current measured star formation rate is insufficient to explain NGC 3226's global UV-optical "green" colors via the resurgence of star formation in a "red and dead" galaxy. This form of "cold accretion" from a tidal stream would appear to be an inefficient way to rejuvenate early-type galaxies and may actually inhibit star formation.

UR - http://arxiv.org/abs/1410.7347

UR - http://dx.doi.org/10.1088/0004-637X/797/2/117

U2 - 10.1088/0004-637X/797/2/117

DO - 10.1088/0004-637X/797/2/117

M3 - Article

VL - 797

SP - 117

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

ER -