English
Related papers

Related papers: Molecular Hydrogen and [FeII] in Active Galactic N…

200 papers

Aims: We present a near-infrared spectral atlas of 47 active galactic nuclei (AGN), of all degrees of activity, in the wavelength interval of 0.8-2.4 microns, including the fluxes of the observed emission lines. We analyze the spectroscopic…

Astrophysics · Physics 2009-11-11 R. Riffel , A. Rodriguez-Ardila , M. G. Pastoriza

We present the first results of an analysis of the properties of the molecular gas in the nuclear regions (r < 300 pc) of a sample of six nearby galaxies, based on new high spatial resolution observations obtained in the K-band with the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 X. Mazzalay , R. P. Saglia , Peter Erwin , M. H. Fabricius , S. P. Rusli , J. Thomas , R. Bender , M. Opitsch , N. Nowak , Michael J. Williams

It was suggested that the prominent feature of the optical Fe II emission has a connection with the accretion process in active galactic nuclei (AGN). For a large sample of 4037 quasars ($z < 0.8$) with measured $\rm H\beta$ line dispersion…

Astrophysics of Galaxies · Physics 2022-10-04 Liu Y. S. , Bian W. H.

For more than twenty years, strong Fe II emission lines have been observed in Active Galactic Nuclei and in particular in Narrow Line Seyfert 1 galaxies. A quick overview of the observations and of the models proposed to interpret the Fe II…

Astrophysics · Physics 2009-10-31 S. Collin , M. Joly

This is the third in a series of papers reporting on a large reverberation-mapping campaign aimed to study the properties of active galactic nuclei (AGNs) with high accretion rates. We present new results on the variability of the optical…

Astrophysics of Galaxies · Physics 2015-05-27 Chen Hu , Pu Du , Kai-Xing Lu , Yan-Rong Li , Fang Wang , Jie Qiu , Jin-Ming Bai , Shai Kaspi , Luis C. Ho , Hagai Netzer , Jian-Min Wang

We investigated the optical FeII emission in a sample of about 215 low-redshift AGN (quasars and luminous Seyfert 1 galaxies). We find that a scaled and broadened FeII template based on the I Zw 1 spectrum can satisfactorily model the FeII…

Astrophysics · Physics 2007-05-23 C. Bongardo , R. Zamanov , P. Marziani , M. Calvani , J. W. Sulentic

We present near and mid--IR observations of a sample of Seyfert II galaxies drawn from the $12\mu$m Galaxy Sample. The sample was observed in the J, H, K, L, M and N bands. Galaxy Surface Brightness Profiles are modeled using nuclear,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Liza Videla , Paulina Lira , Heather Andrews , Almudena Alonso-Herrero , David M. Alexander , Martin Ward

We present theoretical FeII emission line strengths for physical conditions typical of Active Galactic Nuclei with Broad-Line Regions. The FeII line strengths were computed with a precise treatment of radiative transfer using extensive and…

Astrophysics · Physics 2009-11-07 T. A. A. Sigut , Anil K. Pradhan

We analyse 2,015 mid-infrared (MIR) spectra of galaxies observed with Spitzer's Infrared Spectrograph, including objects with growing super-massive black holes and objects where most of the infrared emission originates from newly formed…

Astrophysics of Galaxies · Physics 2019-10-01 Erini L. Lambrides , Andreea O. Petric , Kirill Tchernyshyov , Nadia L. Zakamska , Duncan J. Watts

The protostellar outflow HH211 is of considerable interest since it is extremely young and highly collimated. Here, we explore the outflow through imaging and spectroscopy in the near-infrared to determine if there are further diagnostic…

We use a sample of Type 1 active galactic nuclei (AGNs) spectra in order to investigate which atomic processes are responsible for some observed properties of the FeII emission lines and how they are connected with macroscopic physical…

Astrophysics of Galaxies · Physics 2025-02-26 Jelena Kovačević-Dojčinović , Ivan Dojčinović , Maša Lakićević , Luka Č. Popović

The HeII (1640 A) line and the resonance doublet of NV (UV1) provide a good diagnostic tool to constrain the excitation mechanism of hot (Te>40,000K) atmospheric/magnetospheric plasmas in T Tauri stars (TTSs). Making use of the data…

Solar and Stellar Astrophysics · Physics 2015-06-16 Ana I Gomez de Castro

We report the first direct detection of molecular hydrogen associated with the Galactic nuclear wind. The Far-Ultraviolet Spectroscopic Explorer spectrum of LS 4825, a B1 Ib-II star at $l,b$ = 1.67$^{\circ}$,$-$6.63$^{\circ}$ lying $d$ =…

In this study, a refined approach for multicomponent fitting of active galactic nuclei (AGN) spectra is presented utilizing the newly developed Python code $fantasy$ (fully automated python tool for AGN spectra analysis). AGN spectra are…

Astrophysics of Galaxies · Physics 2023-07-19 Dragana Ilic , Nemanja Rakic , Luka C. Popovic

We present near infrared (IR) spectra (0.98--2.5 mu m) from the group of Herbig-Haro (HH) objects comprising HH99: a series of knots forming a bow, HH99B, and a separate knot, HH99A. Observations of H2, [Fe II] and [C I] are used to…

Astrophysics · Physics 2009-11-10 C. McCoey , T. Giannini , D. R. Flower , A. Caratti o Garatti

The complete near infrared (0.9-2.5 micron) spectra in three different star forming regions (HH24-26, HH72 and BHR71) are presented and analyzed in the framework of shock excitation models. The spectra are dominated by H_2 rovibrational…

Astrophysics · Physics 2009-11-10 T. Giannini , C. McCoey , A. Caratti o Garatti , B. Nisini , D. Lorenzetti , D. R. Flower

High resolution spectra of the Spitzer Space Telescope show vibration-rotation absorption bands of gaseous C2H2, HCN, and CO2 molecules toward a sample of deeply obscured (U)LIRG nuclei. The observed bands reveal the presence of dense (n>~…

A rich spectrum of molecular hydrogen (H$_2$) emission lines is seen in sensitive observations from the far ultraviolet (FUV) channels of the Interface Region Imaging Spectrograph (IRIS) during flare activity in solar active region NOAA…

Solar and Stellar Astrophysics · Physics 2024-10-08 Sarah A. Jaeggli , Adrian N. Daw

The nuclei of merging galaxies are often deeply buried in dense layers of gas and dust. In these regions, gas outflows driven by starburst and AGN activity are believed to play a crucial role in the evolution of these galaxies. However, to…

[Abridged] We present a multi-line study of the kinematics of the molecular and ionised gas phases in the central 2 kpc of NGC6240, based on JWST/NIRSpec and ALMA observations. We devised a new spectral-line fitting approach to de-blend…