The starburst galaxy NGC 7714

Gonzalez-Delgado, R. M.; Pérez, E.; Díaz, Ángeles I.; García-Vargas, María Luisa; Terlevich, Elena; Vı́lchez, J. M.

doi:10.1086/175201

Cited by 80 publications

(90 citation statements)

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“…New long-slit observations at several position angles were obtained by González- Delgado et al (1995), confirming the presence of broad He ii λ4686 in the nucleus. Nebular emission can also be suspected from their spectrum.…”

mentioning

confidence: 66%

New catalogue of Wolf-Rayet galaxies and high-excitation extra-galactic Hii regions

Contini

Pindao

1999

Astron. Astrophys. Suppl. Ser.

184

257

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Abstract. We present a new compilation of Wolf-Rayet (WR) galaxies and extra-galactic Hii regions showing broad He ii λ4686 emission drawn from the literature. Relevant information on the presence of other broad emission lines (N iii λ4640, C iv λ5808 and others) from WR stars of WN and WC subtypes, and other existing broad nebular lines is provided.In total we include 139 known WR galaxies. Among these, 57 objects show both broad He ii λ4686 and C iv λ5808 features. In addition to the broad (stellar) He ii λ4686 emission, a nebular He ii component is well established (suspected) in 44 (54) objects. We find 19 extra-galatic Hii regions without WR detections showing nebular He ii λ4686 emission.The present sample can be used for a variety of studies on massive stars, interactions of massive stars with the ISM, stellar populations, starburst galaxies etc. The data is accessible electronically and will be updated periodically.

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mentioning

confidence: 66%

New catalogue of Wolf-Rayet galaxies and high-excitation extra-galactic Hii regions

Contini

Pindao

1999

Astron. Astrophys. Suppl. Ser.

184

257

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“…Gonzalez-Delgado et al 1995;Gallego et al 1996) is also far more common among massive star-forming systems than in low-mass systems (see Pérez-González et al 2003). It is precisely in these objects where complete obscuration effects in Hα (that would reduce the value a IR ) might occur.…”

Section: Stellar Mass Dependence Of a Ir In Hybrid Tracersmentioning

confidence: 99%

Star formation in the local Universe from the CALIFA sample

Catalán-Torrecilla

Paz

Castillo-Morales

et al. 2015

A&A

127

172

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Context. The star formation rate (SFR) is one of the main parameters used to analyze the evolution of galaxies through time. The need for recovering the light reprocessed by dust commonly requires the use of low spatial resolution far-infrared data. Recombination line luminosities provide an alternative, although uncertain dust-extinction corrections based on narrowband imaging or long-slit spectroscopy have traditionally posed a limit to their applicability. Integral field spectroscopy (IFS) is clearly the way to overcome this kind of limitation. Aims. We obtain integrated Hα, ultraviolet (UV) and infrared (IR)-based SFR measurements for 272 galaxies from the CALIFA survey at 0.005 < z < 0.03 using single-band and hybrid tracers. We aim to determine whether the extinction-corrected Hα luminosities provide a good measure of the SFR and to shed light on the origin of the discrepancies between tracers. Updated calibrations referred to Hα are provided. The well-defined selection criteria and large statistics allow us to carry out this analysis globally and split by properties, including stellar mass and morphological type. Methods. We derive integrated, extinction-corrected Hα fluxes from CALIFA, UV surface and asymptotic photometry from GALEX and integrated WISE 22 µm and IRAS fluxes. Results. We find that the extinction-corrected Hα luminosity agrees with the hybrid updated SFR estimators based on either UV or Hα plus IR luminosity over the full range of SFRs (0.03−20 M yr −1 ). The coefficient that weights the amount of energy produced by newly-born stars that is reprocessed by dust on the hybrid tracers, a IR , shows a large dispersion. However, this coefficient does not became increasingly small at high attenuations, as expected if significant highly-obscured Hα emission were missed, i.e., after a Balmer decrement-based attenuation correction is applied. Lenticulars, early-type spirals, and type-2 AGN host galaxies show smaller coefficients because of the contribution of optical photons and AGN to dust heating. Conclusions. In the local Universe, the Hα luminosity derived from IFS observations can be used to measure SFR, at least in statisticallysignificant, optically-selected galaxy samples, once stellar continuum absorption and dust attenuation effects are accounted for. The analysis of the SFR calibrations by galaxies properties could potentially be used by other works to study the impact of different selection criteria in the SFR values derived, and to disentangle selection effects from other physically motivated differences, such as environmental or evolutionary effects.

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“…A detailed optical study of this system has been made by González-Delgado et al (1995). The 6-cm radio map shows a weak double radio structure (separation 1 arcsec).…”

Section: Ngc 7714 (Arp 284 Mrk 538)mentioning

confidence: 99%

“…On the other hand, starburst galaxies can be defined as 'spiral galaxies with a bright nucleus that is bluer than expected for its morphological type, which emits strong narrow emission lines similar to low ionization H II regions as a consequence of photoionization by the ultraviolet radiation from hot stars, with a typical H luminosity of 10 40 -10 42 erg s 21 ' (González- Delgado et al 1995). These definitions of starburst and WR galaxies should be considered as general criteria rather than as hard rules.…”

Section: Introductionmentioning

confidence: 99%

A ROSAT survey of Wolf—Rayet galaxies

Stevens¹,

Strickland²

1998

Monthly Notices of the Royal Astronomical Society

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A B S T R A C TWe present results from a ROSAT Position Sensitive Proportional Counter (PSPC) survey of the X-ray emission from Wolf-Rayet (WR) galaxies, a class of galaxies believed to be young starbursts (with ages of t#4-6 Myr), many of which are blue compact dwarf galaxies. Of the 36 WR galaxies listed in the catalogue of Conti, a total of 14 have been observed deliberately or serendipitously with the ROSAT PSPC, and of these, seven have been detected.The derived X-ray luminosities of WR galaxies range over nearly three orders of magnitude, from L X #4 10 38 s 21 to 2 10 41 erg s 21. The X-ray spectra of the WR galaxies can typically be well-fitted with a single temperature Raymond-Smith spectral model, with a temperature in the range kT:0.3-1.0 keV, with the general trend that the more X-ray-luminous WR galaxies have hotter spectra. WR galaxies are significantly X-ray-overluminous for their blue luminosity, compared with a sample of nearby spiral and starburst galaxies. In addition, the X-ray luminosity of WR galaxies correlates well with the far-infrared luminosity L FIR and the number of Lyman continuum photons N Lyc . No strong correlation was found with the equivalent width of the WR emission feature around 4686 Å, the presence of which essentially defines the class of galaxies. There is little evidence of extended X-ray emission.Various explanations for the observed properties of WR galaxies are explored, and we conclude that the X-ray emission provides strong evidence that a large fraction of the observed X-rays are coming from a hot superbubble formed by the combined action of stellar winds from massive early-type stars in the central starburst cluster. These results are consistent with, and add weight to, the view that WR galaxies are young starbursts, in which the duration of the star-forming epoch was very short, and that we are viewing them a few Myr after the initiation of the starburst. As such, WR galaxies represent an important epoch in the evolution of starburst galaxies.

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The starburst galaxy NGC 7714

Cited by 80 publications

References 0 publications

New catalogue of Wolf-Rayet galaxies and high-excitation extra-galactic Hii regions

New catalogue of Wolf-Rayet galaxies and high-excitation extra-galactic Hii regions

Star formation in the local Universe from the CALIFA sample

A ROSAT survey of Wolf—Rayet galaxies

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