Super star clusters and their emission lines

AbstractSuper star clusters (SSCs) are young massive objects typically observed in starburst galaxies. They consist of millions of stars occupying volumes only several parsecs across. Recent infrared observations of SSCs reveal strong emission lines with moderately supersonic widths (FWHM ~ 50 – 100 km s−1). An additional, much broader and weaker line component is present in some cases. Using 2D and 3D hydrodynamic simulations, we study models of SSCs in the so-called bimodal regime, which occurs if the stellar density inside the cluster exceeds a certain limit. We confirm the existence of the bimodal solution predicted analytically and suggest an explanation for double-component line profiles: the narrow component is formed close to the cluster center by repressurizing shocks compressing the rarefied gas cooled down due to the thermal instability into dense cold clumps, while the broad component is created by the wind, which cools down at a certain distance from the cluster.

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Subarcsecond Resolution Mid-Infrared Observations of Super Star Clusters in the Antennae (NGC 4038/4039)

The Astrophysical Journal ◽

10.1086/507424 ◽

2006 ◽

Vol 648 (1) ◽

pp. L25-L28 ◽

Cited By ~ 10

Author(s):

L. Snijders ◽

P. P. van der Werf ◽

B. R. Brandl ◽

S. Mengel ◽

D. Schaerer ◽

...

Keyword(s):

Star Clusters ◽

Mid Infrared ◽

Infrared Observations ◽

Super Star Clusters

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Long-Slit Spectroscopy of IC 5135 and NGC 4388

Symposium - International Astronomical Union ◽

10.1017/s0074180900141737 ◽

1989 ◽

Vol 134 ◽

pp. 480-481

Author(s):

Joseph C. Shields ◽

Alexei V. Filippenko

Keyword(s):

Stellar Population ◽

Emission Lines ◽

H Ii Regions ◽

Strong Emission ◽

Narrow Component ◽

Line Intensities ◽

Relative Line ◽

Two Component ◽

The Galaxy ◽

Emission Line Profile

The nucleus of the peculiar Sa galaxy IC 5135 has strong emission lines whose relative intensities resemble those of Seyfert 2 galaxies (Phillips, Charles, and Baldwin 1983). However, the galaxy exhibits relative line intensities such as [O III] λ5007/Hβ = 6.5 and He II λ4686/Hβ = 0.17 that are considerably smaller than typical Seyfert 2 values of 11 and 0.3, respectively (Koski 1978). New, high-resolution spectra (FWHM ≈ 2Å) obtained at Las Campanas Observatory reveal that the Hβ emission-line profile actually consists of a relatively strong, narrow component (FWHM ≈ 250 km s−1) superposed on a much weaker, broad base (FWHM ≈ 1000 km s−1; Fig. 1). A similar two-component profile is evident in [O I] λ6300, whose narrow core probably comes from circumnuclear H II regions that produce little [O III] and He II emission. The strong, high-order Balmer absorption lines are consistent with the presence of a young stellar population in the nucleus.

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Sub-Arcsecond 2.2 micron Imaging of the Starburst Galaxy NGC 1808: Infrared Observations of Super Star Clusters

The Astronomical Journal ◽

10.1086/118065 ◽

1996 ◽

Vol 112 ◽

pp. 918 ◽

Cited By ~ 32

Author(s):

L. E. Tacconi-Garman ◽

A. Sternberg ◽

A. Eckart

Keyword(s):

Star Clusters ◽

Starburst Galaxy ◽

Infrared Observations ◽

Super Star Clusters

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The SAMI Galaxy Survey: reconciling strong emission line metallicity diagnostics using metallicity gradients

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab205 ◽

2021 ◽

Vol 502 (3) ◽

pp. 3357-3373

Author(s):

Henry Poetrodjojo ◽

Brent Groves ◽

Lisa J Kewley ◽

Sarah M Sweet ◽

Sebastian F Sanchez ◽

...

Keyword(s):

Emission Line ◽

Electron Temperature ◽

Gas Phase ◽

Mass Range ◽

Accurate Method ◽

Emission Lines ◽

Mass Relation ◽

Strong Emission ◽

Data Release ◽

Accurate Comparison

ABSTRACT We measure the gas-phase metallicity gradients of 248 galaxies selected from Data Release 2 of the SAMI Galaxy Survey. We demonstrate that there are large systematic discrepancies between the metallicity gradients derived using common strong emission line metallicity diagnostics. We determine which pairs of diagnostics have Spearman’s rank coefficients greater than 0.6 and provide linear conversions to allow the accurate comparison of metallicity gradients derived using different strong emission line diagnostics. For galaxies within the mass range 8.5 < log (M/M⊙) < 11.0, we find discrepancies of up to 0.11 dex/Re between seven popular diagnostics in the metallicity gradient–mass relation. We find a suggestion of a break in the metallicity gradient–mass relation, where the slope shifts from negative to positive, occurs between 9.5 < log (M/M⊙) < 10.5 for the seven chosen diagnostics. Applying our conversions to the metallicity gradient–mass relation, we reduce the maximum dispersion from 0.11 dex/Re to 0.02 dex/Re. These conversions provide the most accurate method of converting metallicity gradients when key emission lines are unavailable. We find that diagnostics that share common sets of emission line ratios agree best, and that diagnostics calibrated through the electron temperature provide more consistent results compared to those calibrated through photoionization models.

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Relationship between intensities of strong emission lines in the spectra of H II regions and their chemical compositions

Kinematics and Physics of Celestial Bodies ◽

10.3103/s0884591312040046 ◽

2012 ◽

Vol 28 (4) ◽

pp. 189-202 ◽

Cited By ~ 3

Author(s):

B. Ya. Melekh ◽

L. S. Pilyugin ◽

R. I. Korytko

Keyword(s):

Emission Lines ◽

Chemical Compositions ◽

H Ii Regions ◽

Strong Emission

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Dissecting quasars with the J-PAS narrow-band photometric survey

Proceedings of the International Astronomical Union ◽

10.1017/s1743921320002483 ◽

2019 ◽

Vol 15 (S356) ◽

pp. 12-16

Author(s):

Silvia Bonoli ◽

Giorgio Calderone ◽

Raul Abramo ◽

Jailson Alcaniz ◽

Narciso Benitez ◽

...

Keyword(s):

Emission Line ◽

Wavelength Range ◽

Software Package ◽

Narrow Band ◽

Active Galaxies ◽

Emission Lines ◽

Low Resolution ◽

Strong Emission ◽

Optical Wavelength ◽

Quasar Spectra

AbstractThe J-PAS survey will soon start observing thousands of square degrees of the Northern Sky with its unique set of 56 narrow band filters covering the entire optical wavelength range, providing, effectively, a low resolution spectra for every object detected. Active galaxies and quasars, thanks to their strong emission lines, can be easily identified and characterized with J-PAS data. A variety of studies can be performed, from IFU-like analysis of local AGN, to clustering of high-z quasars. We also expect to be able to extract intrinsic physical quasar properties from the J-PAS pseudo-spectra, including continuum slope and emission line luminosities. Here we show the first attempts of using the QSFit software package to derive the properties for 22 quasars at 0.8 < z < 2 observed by the miniJPAS survey, the first deg2 of J-PAS data obtained with an interim camera. Results are compared with the ones obtained by applying the same software to SDSS quasar spectra.

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