NGC 2782: a merger remnant with young stars in its gaseous tidal tail★

Torres-Flores, S.; Oliveira, C. Mendes de; Mello, D. F. de; Scarano, Sergio; Urrutia-Viscarra, F.

doi:10.1111/j.1365-2966.2012.20589.x

Cited by 17 publications

(32 citation statements)

References 79 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The internal extinctions (i. e. the color excesses) measured for the star-forming regions in the NGC 6845 system have values E(B-V)=0.50-0.94 that agree with the values found in star forming regions located in other interacting systems e.g. NGC 2856, NGC 2782 and NGC 92 (see Smith et al 2008, Torres-Flores et al 2012.…”

Section: Ages and Internal Extinctions Of The Star-forming Regionssupporting

confidence: 75%

“…These works were focused on the study of metallicity gradients of interacting galaxies up to twice the optical radii of the galaxies but none of them dealt with galaxies with tidal tails. In an attempt to probe metallicities at increasingly larger radii, our group has focused on deriving metallicity gradients for galaxies with long tidal tails in arXiv:1508.05070v1 [astro-ph.GA] 20 Aug 2015 the optical and Hi as is the case of the galaxies NGC 92 (Torres-Flores et al 2014) and NGC 2782 (Werk et al 2011, Torres-Flores et al 2012. The presence of tidal tails allows probing metallicities not only to much outer radii than in cases of galaxies with no tails, but also in the intragroup medium, where intergalactic Hii regions are found (as it is the case for Stephan's quintet, Trancho et al 2012).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

NGC 6845: metallicity gradients and star formation in a complex compact group

Olave-Rojas

Torres-Flores

Carrasco

et al. 2015

Mon. Not. R. Astron. Soc.

Self Cite

View full text Add to dashboard Cite

We have obtained Gemini/GMOS spectra of 28 regions located across the interacting group NGC 6845, spanning from the inner regions of the four major galaxies (NGC 6845A, B, C, D) to the tidal tails of NGC 6845A. All regions in the tails are starforming objects with ages younger than 10 Myr. We derived the gas-phase metallicity gradients across NGC 6845A and its two tails and we find that these are shallower than those for isolated galaxies. NGC 6845A has a gas-phase oxygen central metallicity of 12+log(O/H)∼8.5 and a flat gas-phase metallicity gradient (β=0.002±0.004 dex kpc −1 ) out to ∼4 × R 25 (to the end of the longest tidal tail). Considering the mass-metallicity relation, the central region of NGC 6845A displays a lower oxygen abundance than the expected for its mass. Taking into account this fact and considering the flat oxygen distribution measured along the eastern tidal tail, we suggest that an interaction event has produced a dilution in the central metallicity of this galaxy and the observed flattening in its metal distribution. We found that the star formation process along the eastern tidal structure has not been efficient enough to increase the oxygen abundances in this place, suggesting that this structure was formed from enriched material.

show abstract

Section: Ages and Internal Extinctions Of The Star-forming Regionssupporting

confidence: 75%

Section: Introductionmentioning

confidence: 99%

NGC 6845: metallicity gradients and star formation in a complex compact group

Olave-Rojas

Torres-Flores

Carrasco

et al. 2015

Mon. Not. R. Astron. Soc.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The H i tidal tails hosts recent star formation: Several star-forming regions were found in the FUV and NUV by Torres-Flores et al (2012) in the western tail, as well as in Hα (Werk et al 2011). Knierman et al (2013) found [C ii] emission at the location of the three most luminous Hα sources in the eastern tail, but also a lack of CO and [C ii] associated with the brighter Hα sources in the western tail.…”

Section: Introductionmentioning

confidence: 99%

Superwind evolution: the young starburst-driven wind galaxy NGC 2782

Bravo-Guerrero

Stevens

2017

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We present results from a 30 ksec Chandra observation of the important starburst galaxy NGC 2782, covering the 0.3-10 keV energy band. We find evidence of a superwind of small extent, that is likely in an early stage of development.We find a total of 27 X-ray point sources within a region of radius 2D 25 of the galaxy centre and which are likely associated with the galaxy. Of these, 13 are ULXs (L X 10 39 erg s −1 ) and a number have likely counterparts. The X-ray luminosities of the ULX candidates are 1.2 − 3.9 × 10 39 erg s −1 . NGC 2782 seems to have an unusually large number of ULXs.Central diffuse X-ray emission extending to ∼ 3 kpc from the nuclear region has been detected. We also find an X-ray structure to the south of the nucleus, coincident with Hα filaments and with a 5 GHz radio source. We interpret this as a blow-out region of a forming superwind. This X-ray bubble has a total luminosity (0.3-10 keV) of 5 × 10 39 erg s −1 (around 15% of the total luminosity of the extended emission), and an inferred wind mass of 1.5 × 10 6 M . We also discuss the nature of the central X-ray source in NGC 2782, and conclude that it is likely a low-luminosity AGN (LLAGN), with a total X-ray luminosity of L X = 6 × 10 40 erg s −1 , with strong Fe line emission at 6.4 keV.

show abstract

“…With the detections of these intergalactic systems, we can analyze the probability to form stellar systems in environments where the gas density, HI ∼ 10 19 cm −2 , is very low. In recent years, various authors reported intergalactic objects in interacting systems with gas tails, such as tidal dwarf galaxies (e.g., Duc & Mirabel 1998;Duc et al 2000;Mendes de Oliveira et al 2001;Hibbard et al 2001;de Mello et al 2012;Lee-Waddell et al 2012) and intergalactic HII regions (e.g., Gerhard et al 2002;Ryan-Weber et al 2004;Mendes de Oliveira et al 2004;Arrigoni Battaia et al 2012;Torres-Flores et al 2012;de Mello et al 2012;Yagi et al 2013).…”

Section: Introductionmentioning

confidence: 99%

“…This is commonly observed in pairs or in close interacting galaxies, mainly in the systems, which contain disturbed HI features. Recently, many efforts have been devoted to several systems in the local universe to understand the physical conditions that lead to the formation of new stars and to determine whether these are responsible for polluting the intergalactic medium with metalenriched gas (e.g., Mendes de Oliveira et al 2004); Ryan-Weber et al (2004); Bournaud et al (2004);de Mello et al (2012); Torres-Flores et al (2012); Arrigoni Battaia et al (2012); Yagi et al (2013). These are important points, given that many studies (i.e., Songaila 2001;Pettini et al 2003;Becker et al 2006); Ryan-Weber et al (2006; Simcoe et al (2011);Díaz et al (2011);D'Odorico et al (2013) showed that the intergalactic medium at a redshift of at least 6 is not a pristine remnant of the Big Bang, but rather it contains significant quantities of metals.…”

Section: Introductionmentioning

confidence: 99%

A census of Hαemitters in the intergalactic medium of the NGC 2865 system

Urrutia-Viscarra

Arnaboldi

Oliveira

et al. 2014

A&A

Self Cite

View full text Add to dashboard Cite

Tidal debris, which are rich in HI gas and formed in interacting and merging systems, are suitable laboratories to study star formation outside galaxies. Recently, several such systems were observed, which contained many young star forming regions outside the galaxies. In previous works, we have studied young star forming regions outside galaxies in different systems with optical and/or gaseous tidal debris, in order to understand how often they occur and in which type of environments. In this paper, we searched for star forming regions around the galaxy NGC 2865, a shell galaxy that is circled by a ring of HI with a total mass of 1.2×10 9 M . Using the multi-slit imaging spectroscopy technique with the Gemini telescope, we detected all Hα emitting sources in the surroundings of the galaxy NGC 2865, down to a flux limit of 10 −18 erg cm −2 s −1 Å −1 . With the spectra information and the near and far-ultraviolet flux, we characterize the star formation rates, masses, ages, and metallicities for these HII regions. In total, we found 26 emission-line sources in a 60 × 60 Kpc field centered over the southeastern tail of the HI gas present around the galaxy NGC 2865. Out of the 26 Hα emitters, 19 are in the satellite galaxy FGCE 0745, and seven are intergalactic HII regions scattered over the south tail of the HI gas around NGC 2865. We found that the intergalactic HII regions are young (<200 Myr) with stellar masses in the range 4 × 10 3 M to 17 × 10 6 M . These are found in a region of low HI gas density, where the probability of forming stars is expected to be low. For one of the intergalactic HII regions, we estimated a solar oxygen abundance of 12 + log(O/H) ∼ 8.7. We also were able to estimate the metallicity for the satellite galaxy FGCE 0745 to be 12 + log(O/H) ∼ 8.0. Given these physical parameters, the intergalactic HII regions are consistent with young star forming regions (or clusters), which are born in situ outside the NGC 2865 galaxy from a pre-enriched gas removed from the host galaxies in a merger event. The relevance of these observations is discussed.

show abstract

NGC 2782: a merger remnant with young stars in its gaseous tidal tail★

Cited by 17 publications

References 79 publications

NGC 6845: metallicity gradients and star formation in a complex compact group

NGC 6845: metallicity gradients and star formation in a complex compact group

Superwind evolution: the young starburst-driven wind galaxy NGC 2782

A census of Hαemitters in the intergalactic medium of the NGC 2865 system

Contact Info

Product

Resources

About