Ignacio Negueruela
University of Alicante / Universidad de Alicante, DFISTS, Faculty Member
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LiLiMaRlin is a library of libraries of massive-star high-resolution optical spectra built by collecting data from [a] our spectroscopic surveys (OWN, IACOB. NoMaDS, and CAF\'E-BEANS) and programs and [b] searches in public archives.... more
LiLiMaRlin is a library of libraries of massive-star high-resolution optical spectra built by collecting data from [a] our spectroscopic surveys (OWN, IACOB. NoMaDS, and CAF\'E-BEANS) and programs and [b] searches in public archives. The current version has 18 077 spectra of 1665 stars obtained with seven different telescopes (HET 9.2 m, NOT 2.56 m, CAHA 2.2 m, MPG/ESO 2.2 m, OHP 1.93 m, Mercator 1.2 m, and Stella 1.2 m). All the spectra have been filtered to eliminate misidentifications and bad-quality ones, uniformly reprocessed, and placed on a common format. We present applications of this library of libraries to the analysis of spectroscopic binaries (OWN and MONOS, see poster by E. Trigueros P\'aez at this meeting) and the study of the interstellar medium (CollDIBs). We discuss our plans for the future.
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We present results of our long-term monitoring of LS I +61° 235 in the optical and infrared bands. This Be/X-ray binary exhibits V/R variability in the Hα line, which can be explained in the framework of the Global One-armed Oscillation... more
We present results of our long-term monitoring of LS I +61° 235 in the optical and infrared bands. This Be/X-ray binary exhibits V/R variability in the Hα line, which can be explained in the framework of the Global One-armed Oscillation model: a high density perturbation moves around inside the circumstellar disc of the Be star. The…
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Very recently, a number of obscured massive open clusters have been identified in the Milky Way. A very significant fraction of them lie either close to the base of the Scutum Arm or towards Galactic longitude of 350°. We are studying... more
Very recently, a number of obscured massive open clusters have been identified in the Milky Way. A very significant fraction of them lie either close to the base of the Scutum Arm or towards Galactic longitude of 350°. We are studying these clusters and their neighbourhoods, finding very good evidence for a major starburst region close to the near tip of the Galactic Long Bar.
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We present extensive optical and infrared spectroscopy and photometry, obtained with a suite of telescopes (including VLT), of a sample of counterparts to fast X-ray transients and use them to determine their astrophysical parameters. All... more
We present extensive optical and infrared spectroscopy and photometry, obtained with a suite of telescopes (including VLT), of a sample of counterparts to fast X-ray transients and use them to determine their astrophysical parameters. All the counterparts are OB supergiants. We find that most of these systems are relatively nearby and obscured by large amounts of intervening material.
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We are using a sample of more than 50 standard very late-type stars, taken from Isaac Newton Telescope at R ~ 9000 in the 8100–9100 A range, in order to develop criteria for spectral and luminosity classification of very late-type stars... more
We are using a sample of more than 50 standard very late-type stars, taken from Isaac Newton Telescope at R ~ 9000 in the 8100–9100 A range, in order to develop criteria for spectral and luminosity classification of very late-type stars in the Gaia region. In this article, we brief in a few pages the main challenges on this issue, as well as the literature about it, and we present some preliminary results.
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SAXJ1818.6-1703 was discovered with BeppoSAX in 1998 (in't Zand et al. 1998, IAUC # 6840 ) and observed in outburst more than once (flux of few 10**-9 erg s**-1 cm**-2, Grebenev & Sunyaev 2005,... more
SAXJ1818.6-1703 was discovered with BeppoSAX in 1998 (in't Zand et al. 1998, IAUC # 6840 ) and observed in outburst more than once (flux of few 10**-9 erg s**-1 cm**-2, Grebenev & Sunyaev 2005, AstL 31, 672; Sguera et al. 2005, A&A 444, 221). A Chandra observation in 2006 caught this source at a flux level of of 7.5x10**-12 erg
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The authors present X-ray observations of the Be/X-ray transient 4U 0115+63 taken with the OSSE instrument on board of the Compton Gamma Ray Observatory which show the occurrence of a flare around May 1994. They have studied the evolution... more
The authors present X-ray observations of the Be/X-ray transient 4U 0115+63 taken with the OSSE instrument on board of the Compton Gamma Ray Observatory which show the occurrence of a flare around May 1994. They have studied the evolution of the continuum spectrum and searched for possible changes in the pulse period during the flaring event. They also present long-term
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NGC 7067 is a young open cluster located in the direction between the first and the second Galactic quadrants and close to the Perseus spiral arm. This makes it useful for studies of the nature of the Milky Way spiral arms. Strömgren... more
NGC 7067 is a young open cluster located in the direction between the first and the second Galactic quadrants and close to the Perseus spiral arm. This makes it useful for studies of the nature of the Milky Way spiral arms. Strömgren photometry taken with the Wide Field Camera at the Isaac Newton Telescope allowed us to compute individual physical parameters for the observed stars and hence to derive the cluster's physical parameters. Spectra from the 1.93-m telescope at the Observatoire de Haute-Provence helped to check and improve the results. We obtained photometry for 1233 stars, individual physical parameters for 515 and spectra for 9 of them. The 139 selected cluster members lead to a cluster distance of 4.4 ± 0.4 kpc, with an age below log10(t(yr)) = 7.3 and a present mass of 1260 ± 160 M⊙. The morphology of the data reveals that the centre of the cluster is at (α, δ) = (21: 24: 13.69, +48: 00: 39.2) J2000, with a radius of 6.1 arcmin. Strömgren and spectroscopic data all...
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and other research outputs The identification of the optical/IR counterpart of the 15.8-s transient X-ray pulsar XTE J1946+274 Journal Article
Context. Recent studies have revealed massive star clusters in a region of the Milky Way close to the tip of the Long Bar. These clusters are heavily obscured and are characterised by a population of red supergiants. Aims. We analyse a... more
Context. Recent studies have revealed massive star clusters in a region of the Milky Way close to the tip of the Long Bar. These clusters are heavily obscured and are characterised by a population of red supergiants. Aims. We analyse a previously unreported concentration of bright red stars ∼16′ away from the cluster RSGC1 Methods. We utilised near IR photometry to identify candidate red supergiants and then K-band spectroscopy of a sample to characterise their properties. Results. We find a compact clump of eight red supergiants and five other candidates at some distance, one of which is spectroscopically confirmed as a red supergiant. These objects must form an open cluster, which we name Alicante 8. Because of the high reddening and strong field contamination, the cluster sequence is not clearly seen in 2MASS or UKIDSS near-IR photometry. From the analysis of the red supergiants, we infer an extinction AKS = 1.9 and an age close to 20 Myr. Conclusions. Though this cluster is smal...
We present optical spectroscopy and optical and infrared photometry of the counterpart to the transient X-ray source KS 1947+300. The counterpart is shown to be a moderately reddened V = 14.2 early-type Be star located in an area of low... more
We present optical spectroscopy and optical and infrared photometry of the counterpart to the transient X-ray source KS 1947+300. The counterpart is shown to be a moderately reddened V = 14.2 early-type Be star located in an area of low interstellar absorption slightly above the Galactic plane. Changes in brightness are accompanied by correlated reddening of the source, as is expected in this kind of object. From intermediate resolution spectroscopy, we derive a spectral type B0Ve. If the intrinsic luminosity of the star is normal for its spectral type, KS 1947+300 is situated at a distance of ∼10 kpc, implying that its X-ray luminosity at the peak of the spring 2000 X-ray outburst was typical of Type II outbursts in Be/X-ray transients. KS 1947+300 is thus the first Be/X-ray recurrent transient showing Type II outbursts which has an almost circular orbit.
Open clusters provide natural laboratories to study stellar evolution, as well as astrophysical context for stars in short evolutionary stages. To investigate the divide between stars that will die as supernovae and those which will end... more
Open clusters provide natural laboratories to study stellar evolution, as well as astrophysical context for stars in short evolutionary stages. To investigate the divide between stars that will die as supernovae and those which will end their days as heavy white dwarfs, we are conducting a comprehensive study of open clusters in the age range from ∼30 to 100 Myr. Our sample is limited to clusters with a sizeable population of evolved stars, which can provide constraints individually. The oldest cluster in our sample, NGC 6067, presents a very large population of red giants with masses of 6M and two Cepheids occurring at supersolar metallicity, for which Padova models predict that blue loops will not extend to the instability strip. Our clusters cover a broad range of metallicities, but the strong effects predicted by evolutionary models are not readily seen in the observational diagrams. The distribution of spectral types seems to be driven mainly by age. Combination of data for our...
Young open clusters are the natural laboratories to constrain stellar evolution models. During my PhD thesis we studied the red (super)giants hosted in six open clusters with the aim of exploring the boundary between AGB stars and RSGs.... more
Young open clusters are the natural laboratories to constrain stellar evolution models. During my PhD thesis we studied the red (super)giants hosted in six open clusters with the aim of exploring the boundary between AGB stars and RSGs. These clusters (NGC 2345, NGC 3105, NGC 6067, NGC 6649, NGC 6664 and Trumpler 35) were selected taking into account that their evolved stars, K (super)giants, covered the mass transition (5.5–9.5 M ) around the minimum mass which produces a supernova explosion. By combining photometry and low/moderate-resolution spectroscopy, we studied the clusters in order to obtain accurate ages (and masses) for their evolved stars. From FEROS spectra of the FGK (super)giants contained in the clusters we derived their stellar atmospheric parameters as well as their chemical abundances. Besides the characterization of each cluster, the most complete to date, two remarkable results are found: i) the over-abundance of Ba found in young clusters (30-90 Ma), which supp...
Classical Cepheids in open clusters play an important role in benchmarking stellar evolution models, in addition to anchoring the cosmic distance scale and invariably securing the Hubble constant. Three pertinent clusters hosting... more
Classical Cepheids in open clusters play an important role in benchmarking stellar evolution models, in addition to anchoring the cosmic distance scale and invariably securing the Hubble constant. Three pertinent clusters hosting classical Cepheids and red (super)giants are: NGC 6649, NGC 6664, and Berkeley 55. These clusters form the basis of analysis to assess newly acquired spectra (≈50), archival photometry, andGaiaDR2 data. Importantly, for the first time chemical abundances were determined for the evolved members of NGC 6649 and NGC 6664. We find that they are slightly metal-poor relative to the mean Galactic gradient. Also, an overabundance of Ba is observed. These two clusters likely belong to the thin disc and the latter finding supports the “s-enhanced” scenario of D’Orazi et al. (2009). NGC 6664 and Berkeley 55 exhibit radial velocities consistent with Galactic rotation, while NGC 6649 displays a peculiar velocity. The resulting age estimates for the clusters (≈70 Ma) imp...
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Context. NGC 3105 is a young open cluster hosting blue, yellow, and red supergiants. This rare combination makes it an excellent laboratory for constraining evolutionary models of high-mass stars. It has been poorly studied, and the... more
Context. NGC 3105 is a young open cluster hosting blue, yellow, and red supergiants. This rare combination makes it an excellent laboratory for constraining evolutionary models of high-mass stars. It has been poorly studied, and the fundamental parameters such as its age or distance are not well defined.Aims. We intend to characterise in an accurate way the cluster and its evolved stars, for which we derive for the first time atmospheric parameters and chemical abundances.Methods. We performed a complete analysis combiningUBVRphotometry with spectroscopy. We obtained spectra with classification purposes for 14 blue stars and high-resolution spectroscopy for an in-depth analysis of the six other evolved stars.Results. We identify 126 B-type likely members within a radius of 2.7 ± 0.6 arcmin, which implies an initial mass,Mcl≈ 4100M⊙. We find a distance of 7.2 ± 0.7 kpc for NGC 3105, placing it atRGC= 10.0 ± 1.2 kpc. Isochrone fitting supports an age of 28 ± 6 Ma, implying masses arou...
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We present extensive optical spectroscopy of the early-type magnetic star HD 191612 (O6.5f?pe–O8fp). The Balmer and He i lines show strongly variable emission which is highly reproducible on a well-determined 538-d period. He ii... more
We present extensive optical spectroscopy of the early-type magnetic star HD 191612 (O6.5f?pe–O8fp). The Balmer and He i lines show strongly variable emission which is highly reproducible on a well-determined 538-d period. He ii absorptions and metal lines (including many selective emission lines but excluding He iiλ4686 Å emission) are essentially constant in line strength, but are variable in velocity, establishing a double-lined binary orbit with Porb= 1542 d, e= 0.45. We conduct a model-atmosphere analysis of the spectrum, and find that the system is consistent with a ∼O8 giant with a ∼B1 main-sequence secondary. Since the periodic 538-d changes are unrelated to orbital motion, rotational modulation of a magnetically constrained plasma is strongly favoured as the most likely underlying ‘clock’. An upper limit on the equatorial rotation is consistent with this hypothesis, but is too weak to provide a strong constraint.
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Context.The IACOB and OWN surveys are two ambitious, complementary observational projects which have made available a large multi-epoch spectroscopic database of optical high resolution spectra of Galactic massive O-type stars.Aims.Our... more
Context.The IACOB and OWN surveys are two ambitious, complementary observational projects which have made available a large multi-epoch spectroscopic database of optical high resolution spectra of Galactic massive O-type stars.Aims.Our aim is to study the full sample of (more than 350) O stars surveyed by the IACOB and OWN projects. As a first step towards this aim, we have performed the quantitative spectroscopic analysis of a subsample of 128 stars included in the modern grid of O-type standards for spectral classification. The sample comprises stars with spectral types in the range O3–O9.7 and covers all luminosity classes.Methods.We used the semi-automatizedIACOB-BROADandIACOB-GBAT/FASTWINDtools to determine the complete set of spectroscopic parameters that can be obtained from the optical spectrum of O-type stars. A quality flag was assigned to the outcome of theIACOB-GBAT/FASTWINDanalysis for each star, based on a visual evaluation of how the synthetic spectrum of the best fit...
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Context. The multiplicity properties of massive stars are one of the important outstanding issues in stellar evolution. Quantifying the binary statistics of all evolutionary phases is essential to paint a complete picture of how and when... more
Context. The multiplicity properties of massive stars are one of the important outstanding issues in stellar evolution. Quantifying the binary statistics of all evolutionary phases is essential to paint a complete picture of how and when massive stars interact with their companions, and to determine the consequences of these interactions. Aims. We investigate the multiplicity of an almost complete census of red supergiant stars (RSGs) in NGC 330, a young massive cluster in the Small Magellanic Cloud. Methods. Using a combination of multi-epoch HARPS and MUSE spectroscopy, we estimate radial velocities and assess the kinematic and multiplicity properties of 15 RSGs in NGC 330. Results. Radial velocities are estimated to better than ±100 m s−1 for the HARPS data. The line-of-sight velocity dispersion for the cluster is estimated as σ1D = 3.20 +0.69−0.52 km s−1. When virial equilibrium is assumed, the dynamical mass of the cluster is log (Mdyn/M⊙) = 5.20 ± 0.17, in good agreement with ...
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Context. Multiplicity in massive stars is key to understanding the chemical and dynamical evolution of galaxies. Among massive stars, those of O type play a crucial role due to their high masses and short lifetimes. Aims. MONOS... more
Context. Multiplicity in massive stars is key to understanding the chemical and dynamical evolution of galaxies. Among massive stars, those of O type play a crucial role due to their high masses and short lifetimes. Aims. MONOS (Multiplicity Of Northern O-type Spectroscopic systems) is a project designed to collect information and study O-type spectroscopic binaries with δ > −20°. In this first paper we describe the sample and provide spectral classifications and additional information for objects with previous spectroscopic and/or eclipsing binary orbits. In future papers we will test the validity of previous solutions and calculate new spectroscopic orbits. Methods. The spectra in this paper have two sources: the Galactic O-Star Spectroscopic Survey (GOSSS), a project that obtains blue-violet R ∼ 2500 spectroscopy of thousands of massive stars, and LiLiMaRlin, a library of libraries of high-resolution spectroscopy of massive stars obtained from four different surveys (CAFÉ-BEA...
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Context. The first Gaia Data Release (DR1) significantly improved the previously available proper motions for the majority of the Tycho-2 stars. Aims. We wish to detect runaway stars using Gaia DR1 proper motions and compare our results... more
Context. The first Gaia Data Release (DR1) significantly improved the previously available proper motions for the majority of the Tycho-2 stars. Aims. We wish to detect runaway stars using Gaia DR1 proper motions and compare our results with previous searches. Methods. Runaway O stars and BA supergiants were detected using a 2D proper motion method. The sample was selected using Simbad, spectra from our GOSSS project, literature spectral types, and photometry processed using the code CHORIZOS. Results. We detect 76 runaway stars, 17 (possibly 19) of them with no prior identification as such, with an estimated detection rate of approximately one half of the real runaway fraction. An age effect appears to be present, with objects of spectral subtype B1 and later having traveled for longer distances than runaways of earlier subtypes. We also tentatively propose that the fraction of runaways is lower among BA supergiants that among O stars, but further studies using future Gaia data rel...
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Context. The Galactic supergiant B[e] star CI Camelopardalis (CI Cam) was the first sgB[e] star detected during an X-ray outburst. The star brightened to ∼2 Crab in the X-ray regime (∼5 × 10−8 ergs cm−2 s−1 in the 2–25 keV range) within... more
Context. The Galactic supergiant B[e] star CI Camelopardalis (CI Cam) was the first sgB[e] star detected during an X-ray outburst. The star brightened to ∼2 Crab in the X-ray regime (∼5 × 10−8 ergs cm−2 s−1 in the 2–25 keV range) within hours before decaying to a quiescent level in less than two weeks, clearly indicative of binarity. Since the outburst of CI Cam, several sgB[e] stars have been identified as X-ray overluminous for a single star (i.e. LX > 10−7 Lbol). This small population has recently expanded to include two ultra luminous X-ray sources (ULX), Holmberg II X-1 and NGC 300 ULX-1/supernova imposter SN2010da. Aims. Since the discovery of X-ray emission from CI Cam, there have been many developments in the field of massive binary evolution. In light of the recent inclusion of two ULXs in the population of X-ray bright sgB[e] stars, we revisit CI Cam to investigate its behaviour over several timescales and shed further light on the nature of the compact object in the s...
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Massive stars play an important role in both cluster and galactic evolution and the rate at which they lose mass is a key driver of both their own evolution and their interaction with the environment up to and including their terminal SNe... more
Massive stars play an important role in both cluster and galactic evolution and the rate at which they lose mass is a key driver of both their own evolution and their interaction with the environment up to and including their terminal SNe explosions. Young massive clusters provide an ideal opportunity to study a co-eval population of massive stars, where both their individual properties and the interaction with their environment can be studied in detail. We aim to study the constituent stars of the Galactic cluster Westerlund 1 in order to determine mass-loss rates for the diverse post-main sequence population of massive stars. To accomplish this we made 3mm continuum observations with the Atacama Large Millimetre/submillimetre Array. We detected emission from 50 stars in Westerlund 1, comprising all 21 Wolf-Rayets within the field of view, plus eight cool and 21 OB super-/hypergiants. Emission nebulae were associated with a number of the cool hypergiants while, unexpectedly, a numb...