J/A+A/682/A162 Properties of stellar clumps in stripped tails (Werle+, 2024)
The history of star-forming regions in the tails of 6 GASP jellyfish galaxies
observed with the Hubble Space Telescope.
Werle A., Giunchi E., Poggianti B., Gullieuszik M., Moretti A., Zanella A.,
Tonnesen S., Fritz J., Vulcani B., Bacchini C., Akerman N., Kulier A.,
Tomicic N., Smith R., Wolter A.
<Astron. Astrophys. 682, A162 (2024)>
=2024A&A...682A.162W 2024A&A...682A.162W (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies; Interstellar medium ;
Associations, stellar ; Stars, masses ; Redshifts ; Ultraviolet
Keywords: galaxies: clusters: general - galaxies: evolution - galaxies: ISM -
galaxies: star formation
Abstract:
In this work, we aim to characterize the stellar populations of
star-forming regions detached from the stellar disks of galaxies
undergoing ram-pressure stripping.
Using images collected with the WFC3 camera on board of the Hubble
Space Telescope, we detect stellar clumps in continuum-subtracted
Hα and ultraviolet (F275W filter), such clumps are often
embedded in larger regions (star-forming complexes) detected in the
optical (F606W filter). Our sample includes 347 Hα clumps, 851
F275W clumps and 296 star-forming complexes. We model the photometry
of these objects in 5 bands using bagpipes to obtain their stellar
population parameters.
The median mass-weighted stellar ages are 27Myr for Hα clumps
and 39Myr for F275W clumps and star-forming complexes, but the oldest
stars in the complexes can be older than ∼300Myr which indicates that
star-formation is sustained for long periods of time. Stellar masses
vary from 103.5 to 107.1M☉, with star-forming complexes
being more massive objects in the sample. Clumps and complexes found
further away from the host galaxy are on average younger, less massive
and less obscured by dust. We interpret these trends as due to the
effect of ram-pressure in different phases of the interstellar medium.
Hα clumps form a well-defined sequence in the stellar mass-SFR
plane with slope 0.73. Some F275W clumps and star-forming complexes
follow the same sequence while others stray away from it and passively
age. The difference in mean stellar age between a complex and its
youngest embedded clump scales with the distance between the clump and
the center of the optical emission of the complex, with the most
displaced clumps being hosted by the most elongated complexes. This is
consistent with a fireball-like morphology, where star-formation
proceeds in a small portion of the complex while older stars are left
behind producing a linear stellar population gradient. The stellar
masses of star-forming complexes are consistent with the ones of
globular clusters, but their stellar mass surface densities are lower
by 2dex, and their properties are more consistent with the population
of dwarf galaxies in clusters.
Description:
This catalog contains physical properties of stellar clumps found in
the stripped regions of 6 jellyfish galaxies. Details on the SED
fitting procedure can be fount in section 3 of the paper.
Here we include mean stellar ages, stellar masses and surface
densities, star-formation rates (in a timescale of 10Myr), dust
attenuation (of stars younger than 20Myr) and a classification of the
shape of the star-formation history, along with ancillary data
necessary to reproduce the results of the paper.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 146 1494 Physical properties of stellar clumps
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Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- Object Object ID
20- 38 F19.15 deg RAdeg Right ascension (J2000)
40- 59 F20.16 deg DEdeg Declination (J2000)
61- 65 A5 --- Galaxy Name of host galaxy
67- 74 F8.6 --- zgal Redshift of host galaxy
76- 81 A6 --- Filt Detection filter of the object
(f275w, f606w or halpha)
83- 93 A11 --- Loc Whether the object is located in a tail
(Tail) or in an extraplanar region
(Extraplanar)
95 I1 --- resflag [0/1] Whether the object is considered
resolved
97-101 F5.1 Myr Agemw Mass-weighted age
103-108 F6.4 [Msun] logM* Stellar mass
110-115 F6.4 [Msun/kpc+2] logsigmaM Stellar mass surface density (1)
117-124 F8.4 Msun/yr SFR Star-formation rate
126-131 F6.4 mag Av V-band attenuation (2)
133-146 A14 --- sfhClass Classification of the shape of the
star-formation history
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Note (1): Calculated with respect to the total area of the object, recommended
to use only for resolved objects.
Note (2): For stars younger than 20Myr, recommended to use only for late
decliners.
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Acknowledgements:
Ariel Werle, ariel.werle(at)inaf.it
(End) Patricia Vannier [CDS] 12-Dec-2023