Examinando por Autor "Marques Chaves, R."

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Acceso Abierto
Detection of an ionized gas outflow in the extreme UV-luminous star-forming galaxy BOSS-EUVLG1 at z = 2.47
(EDP Sciences, 2021-03-23) Álvarez Márquez, J.; Marques Chaves, R.; Colina, L.; Pérez Fournon, I.; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
BOSS-EUVLG1 is the most ultraviolet (UV) and Lyα luminous galaxy to be going through a very active starburst phase detected thus far in the Universe. It is forming stars at a rate of 955 ± 118 M⊙ yr−1. We report the detection of a broad Hα component carrying 25% of the total Hα flux. The broad Hα line traces a fast and massive ionized gas outflow characterized by a total mass, log(Mout[M⊙]), of 7.94 ± 0.15, along with an outflowing velocity (Vout) of 573 ± 151 km s−1 and an outflowing mass rate (Ṁout) of 44 ± 20 M⊙ yr−1. The presence of the outflow in BOSS-EUVLG1 is also supported by the identification of blueshifted UV absorption lines in low and high ionization states. The energy involved in the Hα outflow can be explained by the ongoing star formation, without the need for an active galactic nucleus to be included in the scenario. The derived low mass-loading factor (η = 0.05 ± 0.03) indicates that, although it is massive, this phase of the outflow cannot be relevant for the quenching of the star formation, namely, the negative feedback. In addition, only a small fraction (≤15%) of the ionized outflowing material with velocities above 372 km s−1 has the capacity to escape the gravitational potential and to enrich the surrounding circumgalactic medium at distances above several tens of kpc. The ionized phase of the outflow does not carry sufficient mass or energy to play a relevant role in the evolution of the host galaxy nor in the enrichment of the intergalactic medium. As predicted by some recent simulations, other phases of the outflow could be responsible for most of the outflow energy and mass in the form of hot X-ray emitting gas. The expected emission of the extended X-ray emitting halo associated with the outflow in BOSS-EUVLG1 and similar galaxies could be detected with the future ATHENA X-ray observatory, however, there are no methods at present that would assist in their spatial resolution.
Acceso Abierto
Rest-frame UV properties of luminous strong gravitationally lensed Lyα emitters from the BELLS GALLERY Survey
(Oxford Academics: Oxford University Press, 2020-02-10) Marques Chaves, R.; Pérez Fournon, I.; Shu, Y.; Colina, L.; Bolton, A.; Álvarez Márquez, J.; Brownstein, J.; Cornachione, M.; Geier, S.; Jiménez Ángel, C.; Kojima, T.; Mao, S.; Montero Dorta, A.; Oguri, M.; Ouchi, M.; Poidevin, F.; Shirley, Y.; Zheng, Z.; Agencia Estatal de Investigación (AEI); National Science Foundation (NSF); Ministerio de Economía y Competitividad (MINECO); Poidevin, F. [0000-0002-5391-5568]; Marqués Chaves, R. [0000-0001-8442-1846]; Shu, Y. [0000-0002-9063-698X]; Shirley, R. [0000-0002-1114-0135]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
We present deep rest-frame UV spectroscopic observations using the Gran Telescopio Canarias of six gravitationally lensed Ly alpha emitters (LAEs) at 2.36 < z < 2.82 selected from the BELLS GALLERY survey. By taking the magnifications into account, we show that LAEs can be as luminous as L-Ly alpha similar or equal to 30 x 10(42) erg s(-1) and M-UV similar or equal to -23 (AB) without invoking an AGN component, in contrast with previous findings. We measure Ly alpha rest-frame equivalent widths, EW0 (Ly alpha), ranging from 16 to 50 angstrom and Ly alpha escape fractions, f(esc) (Ly alpha), from 10 per cent to 40 per cent. Large EW0 (Ly alpha) and f(esc) (Ly alpha) are found predominantly in LAEs showing weak low-ionization ISM absorption (EW0 less than or similar to 1A) and narrow Ly alpha profiles (less than or similar to 300 km s(-1) FWHM) with their peak close (less than or similar to 80 km s(-1)) to their systemic redshifts, suggestive of less scatter from low HI column densities that favours the escape of Ly alpha photons. We infer stellar metallicities of Z/Z(circle dot) similar or equal to 0.2 in almost all LAEs by comparing the P-Cygni profiles of the wind lines NV1240 angstrom and C IV1549 angstrom with those from stellar synthesis models. We also find a trend between M-UV and the velocity offset of ISM absorption lines, such as the most luminous LAEs experience stronger outflows. The most luminous LAEs show star formation rates up to similar or equal to 180 M-circle dot yr(-1), yet they appear relatively blue (beta(UV) similar or equal to -1.8 to -2.0) showing evidence of little dust attenuation [E(B - V) = 0.10-0.14]. These luminous LAEs may be particular cases of young starburst galaxies that have had no time to form large amounts of dust. If so, they are ideal laboratories to study the early phase of massive star formation, stellar and dust mass growth, and chemical enrichment histories of starburst galaxies at high-z.
Restringido
The discovery of the most UV–Ly α luminous star-forming galaxy: a young, dust- and metal-poor starburst with QSO-like luminosities
(Oxford Academics: Oxford University Press, 2020-09-16) Marques Chaves, R.; Álvarez Márquez, J.; Colina, L.; Pérez Fournon, I.; Schaerer, D.; Dalla Vecchia, C.; Hashimoto, T.; Jiménez Ángel, C.; Shu, Y.; Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); Shu, Y. [0000-0002-9063-698X]; Dalla Vecchia, C. [0000-0002-2620-7056]; Marqués Chaves, R. [0000-0001-8442-1846]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
We report the discovery of BOSS-EUVLG1 at z = 2.469, by far the most luminous, almost un-obscured star-forming galaxy known at any redshift. First classified as a QSO within the Baryon Oscillation Spectroscopic Survey, follow-up observations with the Gran Telescopio Canarias reveal that its large luminosity, M-UV similar or equal to -24.40 and log(L-Ly alpha/erg s(-1)) similar or equal to 44.0, is due to an intense burst of star formation, and not to an active galactic nucleus or gravitational lensing. BOSS-EUVLG1 is a compact (r(eff) similar or equal to 1.2 kpc), young (4-5 Myr) starburst with a stellar mass log(M-*/M-circle dot) = 10.0 +/- 0.1 and a prodigious star formation rate of similar or equal to 1000 M-circle dot yr(-1). However, it is metal- and dust-poor [12+ log(O/H) = 8.13 +/- 0.19, E(B - V) similar or equal to 0.07, log(L-IR/L-UV) < -1.2], indicating that we are witnessing the very early phase of an intense starburst that has had no time to enrich the ISM. BOSS-EUVLG1 might represent a short-lived (<100 Myr), yet important phase of star-forming galaxies at high redshift that has been missed in previous surveys. Within a galaxy evolutionary scheme, BOSS-EUVLG1 could likely represent the very initial phases in the evolution of massive quiescent galaxies, even before the dusty star-forming phase.
Restringido
The UV-brightest Lyman continuum emitting star-forming galaxy
(Oxford Academics: Oxford University Press, 2021-07-30) Marques Chaves, R.; Schaerer, D.; Álvarez Márquez, J.; Colina, L.; Dessauges-Zavadsky, M.; Pérez Fournon, I.; Saldana López, A.; Verhamme, A.; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
We report the discovery of J0121+0025, an extremely luminous and young star-forming galaxy (MUV = −24.11, log[LLyα/erg s−1]=43.8⁠) at z = 3.244 showing copious Lyman continuum (LyC) leakage (⁠fesc,abs≈40 per cent⁠). High signal-to-noise ratio rest-frame UV spectroscopy with the Gran Telescopio Canarias reveals a high significance (7.9σ) emission below the Lyman limit (<912 Å), with a flux density level f900 = 0.78 ± 0.10μJy, and strong P-Cygni in wind lines of O VI 1033 Å, N V 1240 Å, and C IV 1550 Å that are indicative of a young age of the starburst (<10 Myr). The spectrum is rich in stellar photospheric features, for which a significant contribution of an AGN at these wavelengths is ruled out. Low-ionization interstellar medium (ISM) absorption lines are also detected, but are weak (⁠EW0≃1 Å) and show large residual intensities, suggesting a clumpy geometry of the gas with a non-unity covering fraction or a highly ionized ISM. The contribution of a foreground and AGN contamination to the LyC signal is unlikely. Deep optical to Spitzer/IRAC 4.5 μm imaging show that the spectral energy distribution of J0121+0025 is dominated by the emission of the young starburst, with log(⁠Mburst⋆/M⊙)=9.9±0.1 and SFR=981±232 M⊙ yr−1. J0121+0025 is the most powerful LyC emitter known among the star-forming galaxy population. The discovery of such luminous and young starburst leaking LyC radiation suggests that a significant fraction of LyC photons can escape in sources with a wide range of UV luminosities and are not restricted to the faintest ones as previously thought. These findings might shed further light on the role of luminous starbursts to the cosmic reionization.