scholarly journals SpitzerDetection of Polycyclic Aromatic Hydrocarbon and Silicate Dust Features in the Mid‐Infrared Spectra ofz∼ 2 Ultraluminous Infrared Galaxies

2005 ◽  
Vol 628 (2) ◽  
pp. 604-610 ◽  
Author(s):  
Lin Yan ◽  
R. Chary ◽  
L. Armus ◽  
H. Teplitz ◽  
G. Helou ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbon ◽  
Infrared Spectra ◽  
Infrared Galaxies ◽  
Mid Infrared ◽  
Ultraluminous Infrared Galaxies ◽  
Polycyclic Aromatic

Mid‐Infrared Spectra of Polycyclic Aromatic Hydrocarbon Emission in Herbig Ae/Be Stars

2005 ◽  
Vol 632 (2) ◽  
pp. 956-963 ◽  
Author(s):  
G. C. Sloan ◽  
L. D. Keller ◽  
W. J. Forrest ◽  
E. Leibensperger ◽  
B. Sargent ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbon ◽  
Infrared Spectra ◽  
Be Stars ◽  
Mid Infrared ◽  
Polycyclic Aromatic ◽  
Hydrocarbon Emission ◽  
Polycyclic Aromatic Hydrocarbon Emission

scholarly journals Mid‐Infrared and Visible Photometry of Galaxies: Anomalously Low Polycyclic Aromatic Hydrocarbon Emission from Low‐Luminosity Galaxies

2005 ◽  
Vol 624 (1) ◽  
pp. 162-167 ◽  
Author(s):  
David W. Hogg ◽  
Christy A. Tremonti ◽  
Michael R. Blanton ◽  
Douglas P. Finkbeiner ◽  
Nikhil Padmanabhan ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbon ◽  
Mid Infrared ◽  
Polycyclic Aromatic ◽  
Hydrocarbon Emission ◽  
Polycyclic Aromatic Hydrocarbon Emission

scholarly journals Polycyclic aromatic hydrocarbon excitation in nearby spiral galaxies

2020 ◽  
Vol 496 (2) ◽  
pp. 1393-1417 ◽  
Author(s):  
G J Bendo ◽  
N Lu ◽  
A Zijlstra
Keyword(s):  
Star Formation ◽  
Polycyclic Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbon ◽  
Spiral Galaxies ◽  
Dust Emission ◽  
Stellar Populations ◽  
Mid Infrared ◽  
Star Forming ◽  
Evolved Stars ◽  
Polycyclic Aromatic

ABSTRACT We have examined polycyclic aromatic hydrocarbon (PAH) excitation in a sample of 25 nearby face-on spiral galaxies using the ratio of mid-infrared PAH emission to dust mass. Within 11 of the galaxies, we found that the PAH excitation was straightforwardly linked to ultraviolet (UV) or mid-infrared star formation tracers, which, along with other results studying the relation of PAH emission to star formation, indicates that the PAHs are most strongly excited in dusty shells around the star-forming (SF) regions. Within another five galaxies, the PAH emission is enhanced around SF regions only at specific galactocentric radii. In six more galaxies, PAH excitation is more strongly correlated with the evolved stellar populations as traced by 3.6 μm emission. The results for the remaining three galaxies were ambiguous. The radial gradients of the PAH/dust ratios were generally not linked to log(O/H) gradients except when the log(O/H) gradients were relatively steep. Galaxies in which PAHs were excited by evolved stars had relatively high far-UV to mid-infrared ratios, implying that variations in the link between PAH excitation and different stellar populations are connected to changes in dust attenuation within galaxies. Alternately, differences in morphology could make it more likely that PAHs are excited by evolved stars, as five of the six galaxies where this occurs are late-type flocculent spiral galaxies. These heterogeneous results demonstrate the complexity of describing PAH excitation and have broad implications for using PAH emission as a star formation tracer as well as for modelling dust emission and radiative transfer.

scholarly journals A New MIR/submm Diagnostic for Dust-Enshrouded AGN

2002 ◽  
Vol 184 ◽  
pp. 205-212
Author(s):  
Martin Haas
Keyword(s):  
Flux Ratio ◽  
Peak Height ◽  
Dust Grains ◽  
Infrared Galaxies ◽  
Mid Infrared ◽  
Dust Extinction ◽  
Ultraluminous Infrared Galaxies ◽  
Polycyclic Aromatic ◽  
Dust Distribution ◽  
Infrared Extinction

AbstractWe show that the PAH 7.7μm to continuum 850μm flux ratio can be used to reveal high mid-infrared extinction in ultraluminous infrared galaxies (ULIRGs). While the submm radiation is optically thin and represents the emission from essentially all dust grains, the PAH strength (measured by the peak height of the Polycyclic Aromatic Hydocarbonates at 7.7μm) is sensitive to dust extinction in the mid-infrared (MIR). As an application of the new diagnostic, after dereddening of the central MIR continuum and with the assumption of a disk-like dust distribution seen under a tilted angle, we find increasing evidence for a hidden quasar in the archetypal ULIRG Arp220.

Mid-infrared PAH emission from star-forming galaxies selected at 250 μm

2019 ◽  
Vol 15 (S341) ◽  
pp. 281-282
Author(s):  
Seong Jin Kim ◽  
Keyword(s):  
Polycyclic Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbon ◽  
Physical Modeling ◽  
Wide Field ◽  
Mid Infrared ◽  
Star Forming ◽  
Polycyclic Aromatic ◽  
Data Points ◽  
Cold Dust ◽  
Strong Radiation

AbstractThe infrared (IR) galaxies detected at Herschel/SPIRE 250 μm band over the AKARI’s NEP-Wide field are various types of dusty star-forming (SF) galaxies ranging from quiescent to starbursts, having mid-IR polycyclic aromatic hydrocarbon (PAH) features near 8 μm. The measurements of the 8 μm luminosity (L8μm) along with the total infrared luminosity (LIR) based on the physical modeling of SEDs a take unique advantage of the continuous near- to mid-IR coverage, far-IR data points, and spectroscopically determined accurate redshifts. Our sample shows shortage of 8 μm luminosity compared to the total IR luminosity. This deficit gets severe in more luminous IR galaxies, suggesting PAH molecules in these galaxies are destroyed by a strong radiation field from SF regions, or the existence of a unexpectedly large amount of cold dust in the ISM that contributes to LIR.

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