Spitzer Observations of Passive and Star Forming Early-type Galaxies: an Infrared Color-Color Sequence

Abstract

We describe the infrared properties of a large sample of early type galaxies, comparing data from the Spitzer archive with Ks-band emission from 2MASS. While most representations of this data result in correlations with large scatter, we find a remarkably tight relation among colors formed by ratios of luminosities in Spitzer-MIPS (24, 70 and 160 um) bands and the Ks-band. Remarkably, this correlation among E and S0 galaxies follows that of nearby normal galaxies of all morphological types. In particular, the tight infrared color-color correlation for S0 galaxies alone follows that of the entire Hubble sequence of normal galaxies, roughly in order of galaxy type from ellipticals to spirals to irregulars. The specific star formation rate of S0 galaxies estimated from the 24um luminosity increases with decreasing Ks-band luminosity (or stellar mass) from essentially zero, as with most massive ellipticals, to rates typical of irregular galaxies. Moreover, the luminosities of the many infrared-luminous S0 galaxies can significantly exceed those of the most luminous (presumably post-merger) E galaxies. Star formation rates in the most infrared-luminous S0 galaxies approach 1-10 solar masses per year. Consistently with this picture we find that while most early-type galaxies populate an infrared red sequence, about 24% of the objects (mostly S0s) are in an infrared blue cloud together with late type galaxies. For those early-type galaxies also observed at radio frequencies we find that the far-infrared luminosities correlate with the mass of neutral and molecular hydrogen, but the scatter is large. This scatter suggests that the star formation may be intermittent or that similar S0 galaxies with cold gaseous disks of nearly equal mass can have varying radial column density distributions that alter the local and global SF rates.

14 Pages, 13 figures, Accepted by ApJ

References in corpus (14)

• Dust-Corrected Star Formation Rates of Galaxies. I. Combinations of H-alpha and Infrared Tracers
• An Ultraviolet-to-Radio Broadband Spectral Atlas of Nearby Galaxies
• Neutral hydrogen in nearby elliptical and lenticular galaxies: the continuing formation of early-type galaxies
• Molecular Gas and Star Formation in the SAURON Early-type Galaxies
• Galaxy Zoo: A sample of blue early-type galaxies at low redshift
• E/S0 Galaxies on the Blue Color-Stellar Mass Sequence at z=0: Fading Mergers or Future Spirals?
• Absolute Calibration and Characterization of the Multiband Imaging Photometer for Spitzer. III. An Asteroid-based Calibration of MIPS at 160 microns
• Structure and Kinematics of Molecular Disks in Fast-Rotator Early-Type Galaxies
• The Cool ISM in Elliptical Galaxies. I. A Survey of Molecular Gas
• The HI content of Early-Type Galaxies from the ALFALFA survey I. Catalogued HI sources in the Virgo cluster
• The mid-infrared colour-magnitude relation of early-type galaxies in the Coma cluster as measured by Spitzer-IRS
• Mid- to Far-IR Emission and Star Formation in Early-Type Galaxies
• Spitzer Observations of Transient, Extended Dust in Two Elliptical Galaxies: New Evidence of Recent Feedback Energy Release in Galactic Cores
• The Mid-Infrared Spectral Energy Distribution, Surface Brightness and Color Profiles in Elliptical Galaxies

Cited by in corpus (57)

• Discovery of an AGN-Driven Molecular Outflow in the Local Early-Type Galaxy NGC 1266
• The Tully-Fisher relations of early-type spiral and S0 galaxies
• The subarcsecond mid-infrared view of local active galactic nuclei: I. The N- and Q-band imaging atlas
• Mechanical AGN Feedback: Controlling the Thermodynamical Evolution of Elliptical Galaxies
• Early-type galaxies in different environments: an HI view
• The Atlas3D project - XXIV. The intrinsic shape distribution of early-type galaxies
• Molecular gas and star formation in early-type galaxies
• H-ATLAS/GAMA: Dusty early-type galaxies and passive spirals
• Molecular depletion times and the CO-to-H2 conversion factor in metal-poor galaxies
• Are high redshift Galaxies hot? - Temperature of z > 5 Galaxies and Implications on their Dust Properties
• Evidence for Two Phases of Galaxy Formation from Radial Trends in the Globular Cluster System of NGC 1407
• Comprehensive comparison of models for spectral energy distributions from 0.1 micron to 1 mm of nearby star-forming galaxies
• Quiescence correlates strongly with directly-measured black hole mass in central galaxies
• Supermassive black holes as the regulators of star formation in central galaxies
• Herschel-ATLAS/GAMA: a census of dust in optically selected galaxies from stacking at submillimetre wavelengths
• A Survey of the Molecular ISM Properties of Nearby Galaxies using the Herschel FTS
• After The Fall: The Dust and Gas in E+A Post-Starburst Galaxies
• Detection of a High Brightness Temperature Radio Core in the AGN-Driven Molecular Outflow Candidate NGC 1266
• The Origin of Dust in Early-Type Galaxies and Implications for Accretion onto Supermassive Black Holes
• Circumstellar Dust Around AGB Stars and Implications for Infrared Emission from Galaxies
• Threads, Ribbons, and Rings in the Radio Galaxy IC 4296
• The AMIGA sample of isolated galaxies. XI. Optical characterisation of nuclear activity
• The Hubble Space Telescope Cluster Supernova Survey: III. Correlated Properties of Type Ia Supernovae and Their Hosts at 0.9 < z < 1.46
• Star-Formation Bimodality in Early-Type Galaxies
• The ($NUV-r$) vs. $M_r$ as a tracer of early-type galaxies evolution in USGC U376 and LGG 225 groups
• The SAURON Project - XX. The Spitzer [3.6] - [4.5] colour in early-type galaxies: colours, colour gradients and inverted scaling relations
• Star Formation in Nearby Early-Type Galaxies: The Radio Continuum Perspective
• Dust properties and star formation of approximately a thousand local galaxies
• Catching Spiral - S0 transition in groups. Insights from SPH simulations with chemo-photometric implementation
• The Herschel Fornax Cluster Survey I: The Bright Galaxy Sample
• VLA Radio Study of a Sample of Nearby X-ray and Optically Bright Early-Type Galaxies
• Probing multiphase gas in local massive elliptical galaxies via multiwavelength observations
• Galaxy Evolution in Local Group Analogs. I. A GALEX study of nearby groups
• The ATLAS 3D project - XVI. Physical parameters and spectral line energy distributions of the molecular gas in gas-rich early-type galaxies
• The First Mid-IR View of the Star-forming Properties of Nearby Galaxy Groups
• Diffuse X-ray-emitting Gas in Major Mergers
• The Infrared and Radio Fluxes Densities of Galactic HII Regions
• The radial distribution of X-ray Binaries and Globular Clusters in NGC 4649 and their relation with the local stellar mass density
• Transition of BH feeding from the quiescent regime into star-forming cold disk regime
• Herschel Spectroscopy of Early Type Galaxies
• What obscures low X-ray-scattering active galactic nuclei?
• H-ATLAS/GAMA and HeViCS - Dusty Early-Type Galaxies in Different Environments
• The Fornax 3D project: dust mix and gas properties in the center of early-type galaxy FCC 167
• Testing the Universality of the Stellar IMF with Chandra and HST
• Radio continuum and X-ray emission from the most extreme FIR-excess galaxy NGC 1377: An extremely obscured AGN revealed
• The Unusual AGN Host NGC 1266: Evidence for Shocks in a Molecular Gas Rich S0 Galaxy with a Low Luminosity Nucleus
• Variation of Mid and Far-IR Luminosities among Early-Type Galaxies: Relation to Stellar Metallicity and Cold Dust
• NGC 1266: Characterization of the Nuclear Molecular Gas in an Unusual SB0 Galaxy
• Investigating early-type galaxy evolution with a multi-wavelength approach. III. Insights from SPH simulations with chemo-photometric implementation
• ALMA Observations of the Molecular Gas in the Elliptical Galaxy NGC3557
• The Nature of Star Formation at 24 microns in the Group Environment at 0.3 < z < 0.55
• AMUSE-VIRGO. III: mid-infrared photometry of early-type galaxies and limits on obscured nuclear emission
• The Physical Characteristics of Interstellar Medium in NGC 3665 with Herschel Observations
• Searching for Nuclear Obscuration in the Infrared Spectra of Nearby FR I Radio Galaxies
• The tidal filament of NGC 4660
• Mid-IR Enhanced Galaxies in the Coma & Virgo Cluster: lenticulars with a high star formation rate
• Ultrahigh energy cosmic ray nuclei from remnants of dead quasars