scholarly journals MEGARA-IFU detection of extended He ii λ4686 nebular emission in the central region of NGC 1569 and its ionization budget

2020 ◽  
Vol 498 (1) ◽  
pp. 1496-1514
Author(s):  
Y D Mayya ◽  
E Carrasco ◽  
V M A Gómez-González ◽  
J Zaragoza-Cardiel ◽  
A Gil de Paz ◽  
...  

ABSTRACT We here report the detection of extended He ii λ4686 nebular emission in the central region of NGC 1569 using the integral field spectrograph MEGARA at the 10.4 m Gran Telescopio Canarias. The observations cover a field of view (FoV) of 12.5 arcsec × 11.3 arcsec at a seeing-limited spatial resolution of ∼15 pc and at a spectral resolution of R = 6000 in the wavelength range 4330–5200 Å. The emission extends over a semicircular arc of ∼40 pc width and ∼150 pc diameter around the superstar cluster A (SSC-A). The AV derived using Balmer decrement varies from the Galactic value of 1.6 mag to a maximum of ∼4.5 mag, with a mean value of 2.65 ± 0.60 mag. We infer 124 ± 11 Wolf–Rayet (WR) stars in SSC-A using the He ii λ4686 broad feature and AV = 2.3 mag. The He+ ionizing photon rate from these WR stars is sufficient to explain the luminosity of the He ii nebula. The observationally determined total He+ and H0 ionizing photon rates, their ratio, and the observed number of WR stars in SSC-A are all consistent with the predictions of simple stellar population models at an age of 4.0 ± 0.5 Myr and a mass of (5.5 ± 0.5) × 105 M⊙. Our observations reinforce the absence of WR stars in SSC-B, the second most massive cluster in the FoV. None of the other locations in our FoV where He ii λ4686 emission has been reported from narrow-band imaging observations contain WR stars.

2019 ◽  
Vol 15 (S359) ◽  
pp. 448-449
Author(s):  
Johan M. Marques ◽  
Rogemar A. Riffel ◽  
Thaisa Storchi-Bergmann ◽  
Rogério Riffel ◽  
Marlon R. Diniz

AbstractWe present Gemini Near-Infrared Integral-Field Spectrograph (NIFS) observations of the inner 660 × 660 pc2 of the Seyfert 2 galaxy NGC 1125, which reveals that the emission-line profiles present two kinematic components: a narrow one (σ < 150 km s−1) due to emission of the gas in the disk and a broad component (σ > 150 km s−1) produced by a bipolar outflow, perpendicular to the galaxy’s disk.


2014 ◽  
Vol 10 (S309) ◽  
pp. 53-56
Author(s):  
Olga K. Sil'chenko

AbstractI have analyzed line-of-sight velocity fields of the stellar and ionized-gas components for the volume-limited sample of nearby lenticular galaxies by using the raw data of the ATLAS-3D survey undertaken with the integral-field spectrograph SAURON. Among 200 nearby lenticular galaxies, I distinguish 20 cases of nearly orthogonal rotation of the inner ionized gas with respect to the central stellar components; so I estimate a frequency of the inner polar disks in nearby S0 galaxies as 10%. Properties of the central stellar populations – mean ages, metallicities, magnesium-to-iron ratios – are derived through the Lick indices. The typical stellar population properties of the polar-disk host galaxies are exactly the same as the stellar population properties of the complete sample.


2010 ◽  
Author(s):  
Katherine B. Follette ◽  
Laird M. Close ◽  
Derek Kopon ◽  
Jared R. Males ◽  
Victor Gasho ◽  
...  

2020 ◽  
Vol 645 ◽  
pp. A12
Author(s):  
B. Balmaverde ◽  
A. Capetti ◽  
A. Marconi ◽  
G. Venturi ◽  
M. Chiaberge ◽  
...  

We present the final observations of a complete sample of 37 radio galaxies from the Third Cambridge Catalogue (3C) with redshift < 0.3 and declination < 20° obtained with the VLT/MUSE optical integral field spectrograph. These data were obtained as part of the MUse RAdio Loud Emission line Snapshot (MURALES) survey with the main goal of exploring the AGN feedback process in the most powerful radio sources. We present the data analysis and, for each source, the resulting emission line images and the 2D gas velocity field. Thanks to the unprecedented depth these observations reveal emission line regions (ELRs) extending several tens of kiloparsec in most objects. The gas velocity shows ordered rotation in 25 galaxies, but in several sources it is highly complex. We find that the 3C sources show a connection between radio morphology and emission line properties. In the ten FR I sources the line emission region is generally compact, only a few kpc in size; only in one case does it exceed the size of the host. Conversely, all but two of the FR II galaxies show large-scale structures of ionized gas. The median extent is 16 kpc with the maximum reaching a size of ∼80 kpc. There are no apparent differences in extent or strength between the ELR properties of the FR II sources of high and low gas excitation. We confirm that the previous optical identification of 3C 258 is incorrect: this radio source is likely associated with a quasi-stellar object at z ∼ 1.54.


Author(s):  
M. Mingozzi ◽  
G. Venturi ◽  
F. Mannucci ◽  
A. Marconi ◽  
G. Cresci

The central regions of Seyfert galaxies, comprising broad and narrow line regions and the inner parts of galaxy disk and bulge, is characterized by a complex interplay among many physical effects. Specifically, it is shaped by the influence of the central black hole, producing ionization by an hard continuum and gas outflows. The integral-field spectrograph MUSE at the ESO VLT allows to carry out a detailed study of these regions to obtain their ionization, dynamical, and metallicity properties. Here we present some highlights of the MAGNUM survey which is designed to study the central regions of a sample of nearby (D > 500 pc) Seyfert galaxies. We describe the rationale of the survey, the data analysis techniques used to extract information on ionization and dynamics, and the results for one galaxy, Centaurus A.


2018 ◽  
Vol 130 (988) ◽  
pp. 065001 ◽  
Author(s):  
Seth R. Meeker ◽  
Benjamin A. Mazin ◽  
Alex B. Walter ◽  
Paschal Strader ◽  
Neelay Fruitwala ◽  
...  

Author(s):  
Sebastiaan Y. Haffert ◽  
Jared Males ◽  
Laird Close ◽  
Joseph Long ◽  
Lauren Schatz ◽  
...  

1995 ◽  
Vol 149 ◽  
pp. 282-287 ◽  
Author(s):  
Eric Emsellem ◽  
Roland Bacon ◽  
Guy Monnet

AbstractWe conducted an observational program using the TIGER integral field spectrograph to study the dynamical structure of nearby galactic nuclei. We already obtained new original results on three of the best ”Black Holes Candidates”: M 32, M 31 and M 104. Their nuclei exhibit complex morphologies and unusual dynamical properties such as: asymmetries, anisotropy, triaxiality which would have been impossible to detect with a ”classical“ spectrograph.


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