Related papers: PAH emission from Herbig AeBe stars
The physical processes occurring within the inner few astronomical units of proto-planetary disks surrounding Herbig Ae stars are crucial to setting the environment in which the outer planet-forming disk evolves and put critical constraints…
We present near-IR (J,H,Ks) photometry for 27 of the 28 candidate Herbig Ae/Be stars in the Small and Large Magellanic Clouds identified via the EROS1 and EROS2 surveys as well as near-contemporaneous optical (H-alpha) spectroscopy for 21…
We combined mapping-mode mid-infrared Spitzer spectra with complementary infrared imaging to perform a spatially resolved study of polycyclic aromatic hydrocarbons (PAHs) emission from the central regions of 66 nearby galaxies, roughly…
We use archival COBE/DIRBE data to construct a map of polycyclic aromatic hydrocarbon (PAH) emission in the $\lambda$-Orionis region. The presence of the 3.3 $\mu$m PAH feature within the DIRBE 3.5 $\mu$m band and the corresponding lack of…
I summarize the results of two recent studies, based on ISO and Spitzer mid-IR spectra of galaxies and Galactic regions, aimed at understanding the origins of the variations of the aromatic features among and inside galaxies. I show that…
For star-forming galaxies, we investigate a global relation between polycyclic aromatic hydrocarbon (PAH) emission luminosity at 3.3 um, L_PAH3.3, and infrared (8-1000 um) luminosity, L_IR, to understand how the PAH 3.3 um feature relates…
Context. It is now generally accepted that the near-infrared excess of Herbig AeBe stars originates in the dust of a circumstellar disk. Aims. The aims of this article are to infer the radial and vertical structure of these disks at scales…
We examine the UV reprocessing efficiencies of warm dust and polycyclic aromatic hydrocarbons (PAHs) through an analysis of the mid- and far-infrared surface luminosity densities of 85 nearby H$\alpha$-selected star-forming galaxies…
In the present contribution, I summarize a systematic study of ISO and Spitzer mid-IR spectra of Galactic regions and star forming galaxies. This study quantifies the relative variations of the main aromatic features inside spatially…
Astrochemical evolution step of polycyclic aromatic hydrocarbon (PAH) around a Herbig Ae young star was analyzed using the first principles quantum chemical calculation. For simplicity, model molecule was selected to be acenaphthylene…
We use deep Spitzer mid-infrared spectroscopic maps of radial strips across three nearby galaxies with well-studied metallicity gradients (M101, NGC 628, and NGC 2403) to explore the physical origins of the observed deficit of polycyclic…
We study the evolution of the Aromatic Infrared Bands (AIBs) emitters across the illuminated edge of the Horsehead nebula and especially their survival and properties in the HII region. We present spectral mapping observations taken with…
We performed a systematic search for Chandra archival observations of Herbig Ae/Be stars. These stars are fully radiative and not expected to support dynamo action analogous to their convective lower-mass counterparts, the T Tauri stars.…
Using data obtained by the DIRBE and FIRAS instruments on the COBE spacecraft we present the mean 3.5-1000 um dust spectrum from the high latitude cirrus clouds. These data represent the most comprehensive wavelength coverage of dust…
We present linear spectropolarimetric data for eight Herbig Be and four Herbig Ae stars at H alpha, H beta and H gamma. Changes in the linear polarisation are detected across all Balmer lines for a large fraction of the observed objects,…
We present a comparison of observed polycyclic aromatic hydrocarbon (PAH) feature ratios in 19 nearby galaxies with a grid of theoretical expectations for near- and mid-infrared dust emission. The PAH feature ratios are drawn from Cycle 1…
Herbig Ae/Be stars (HAeBe) are pre-main sequence objects in the mass range between 2 and 8 solar masses. Their X-ray properties are uncertain and, as yet, unexplained. We want to elucidate the X-ray generating mechanism in HAeBes. We…
The 11.3 $\mu$m emission feature is a prominent member of the family of unidentified infrared emission (UIE) bands and is frequently attributed to out-of-plane bending modes of polycyclic aromatic hydrocarbon (PAH) molecules. We have…
We analyse the optical and IR spectra, as well as the spectral energy distribution (UV to mm) of the candidate Herbig Ae star HD100453. This star is particular, as it shows an energy distribution similar to that of other isolated Herbig…
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…