Sol Alonso - Academia.edu (original) (raw)
Papers by Sol Alonso
Astronomy & Astrophysics
Context. The zone of avoidance (ZoA) does not allow for clear optical observations of extragalact... more Context. The zone of avoidance (ZoA) does not allow for clear optical observations of extragalactic sources behind the Milky Way due to the meaningful extinction of the optical emission of these objects. Observations in near-infrared (NIR) wavelengths represent a potential source of astronomical discoveries that support the detection of new galaxies and potentially complete the picture of the large-scale structures in this as-yet poorly explored area of the sky. Aims. Our aim is to decipher the nature of the overdensity located behind the Milky Way in tile b204 of the VISTA Variables in Vía Láctea (VVV) survey. Methods. We studied an area of six arcmin around a galaxy concentration located at l = 354.82° and b = −9.81°. We selected five galaxies, taking into account the source distribution on the sky to optimise the requested time for the observations, and we obtained the spectra with Flamingos 2 long-slit spectrograph at Gemini South 8.1-meter telescope. To identify and characteris...
Symposium - International Astronomical Union, 2004
We analyzed the effects of having a close companion on the star formation activity of galaxies in... more We analyzed the effects of having a close companion on the star formation activity of galaxies in the 8K galaxy pair catalog selected from the 2dFGRS. We found that, statistically, galaxies with rp…
Monthly Notices of the Royal Astronomical Society, 2004
Monthly Notices of the Royal Astronomical Society, 2007
Astronomy & Astrophysics, 2012
Cornell University - arXiv, Oct 28, 2022
Astronomy & Astrophysics, 2021
Context. The extragalactic vision we have through the Milky Way is very unclear. There is signifi... more Context. The extragalactic vision we have through the Milky Way is very unclear. There is significant extinction of the optical emission from objects located in the region called the zone of avoidance (ZOA). NIR wavelengths are less affected by extinction, and therefore the infrared surveys in this zone are a potential source of astronomical discoveries. Nevertheless, these observations need to be compared with cosmological simulations in order to carry out high−accuracy studies. Aims. Our aim is to identify extragalactic sources in the ZOA, using infrared images of the VVV survey. We consider mock galaxy catalogues in order to interpret observational results. Methods. We studied a region of 1.636 square degrees corresponding to the VVV tile b204. Using SExtractor, we analysed photometric data generating a catalogue of extended sources in this area. In order to confirm these sources as galaxy candidates we visually inspected RGB images looking for typical galaxy features. Using 2MAS...
Monthly Notices of the Royal Astronomical Society, 2021
We perform a comparative study of active galactic nuclei (AGNs) in pairs, triplets, and groups. T... more We perform a comparative study of active galactic nuclei (AGNs) in pairs, triplets, and groups. To this end, we use the Duplancic et al. catalogue of small galaxy systems and consider BPT and WHAN diagnostic diagrams to select optical AGNs. Also, we identify mid-IR AGNs by using WISE data. We performed a comparison between the different AGN classification methodologies and study the AGN fraction in pairs, triplets, and groups with four to six members. We also analyse the main properties of Optical and mid-IR AGN hosts and the influence of environment on the active nuclei phenomena in these small galaxy systems. Our results show that, regardless the specifically adopted classification scheme, the fraction of AGN in pairs and triplets is always higher than the corresponding fraction in groups. Moreover, the fraction of powerful AGNs in pair and triplets is about twice the fraction of regular AGNs. We also find a remarkable difference between Optical and mid-IR AGNs in groups, where ho...
Astronomy & Astrophysics, 2021
Aims. We present a statistical analysis of different characteristics of ringed spiral galaxies wi... more Aims. We present a statistical analysis of different characteristics of ringed spiral galaxies with the aim of assessing the effects of rings on disk galaxy properties. Methods. We built a catalog of ringed galaxies from the Sloan Digital Sky Survey Data Release 14 (SDSS-DR14). Via visual inspection of SDSS images, we classified the face-on spiral galaxies brighter than g < 16.0 mag into galaxies with: an inner ring, an outer ring, a nuclear ring, both an inner and an outer ring, and a pseudo-ring. In addition to rings, we recorded morphological types and the existence of bars, lenses, and galaxy pair companions with or without interaction. With the goal of providing an appropriate quantification of the influence of rings on galaxy properties, we also constructed a suitable control sample of non-ringed galaxies with similar redshift, magnitude, morphology, and local density environment distributions to those of ringed ones. Results. We found 1868 ringed galaxies, accounting for 2...
Monthly Notices of the Royal Astronomical Society, 2020
We use SDSS-DR14 to construct a sample of galaxy systems consisting of a central object and two s... more We use SDSS-DR14 to construct a sample of galaxy systems consisting of a central object and two satellites. We adopt projected distance and radial velocity difference criteria and impose an isolation criterion to avoid membership in larger structures. We also classify the interaction between the members of each system through a visual inspection of galaxy images, finding sim80rmpercent{\sim}80{{\ \rm per\ cent}}sim80rmpercent of the systems lack evidence of interactions whilst the remaining sim20rmpercent{\sim}20{{\ \rm per\ cent}}sim20rmpercent involve some kind of interaction, as inferred from their observed distorted morphology. We have considered separately, samples of satellites and central galaxies, and each of these samples were tested against suitable control sets to analyse the results. We find that central galaxies showing signs of interactions present evidence of enhanced star formation activity and younger stellar populations. As a counterpart, satellite samples show these galaxies presenting older stellar populations wit...
Monthly Notices of the Royal Astronomical Society, 2018
Monthly Notices of the Royal Astronomical Society, 2018
Physical Review Letters, 2019
Astronomy & Astrophysics, 2018
Aims. With the aim of performing a suitable comparison of the internal process of galactic bars w... more Aims. With the aim of performing a suitable comparison of the internal process of galactic bars with respect to the external effect of interactions on driving gas toward the inner most region of the galaxies, we explored and compared the efficiency of both mechanisms on central nuclear activity in optically selected active galactic nuclei (AGNs) in spiral galaxies. Methods. We selected homogeneous samples of barred AGNs and active objects residing in pair systems, derived from the Sloan Digital Sky Survey (SDSS). In order to carry out a reliable comparison of both samples (AGNs in barred hosts in isolation and in galaxy pairs), we selected spiral AGN galaxies with similar distributions of redshift, magnitude, stellar mass, color and stellar age population from both catalogs. With the goal of providing an appropriate quantification of the influence of strong bars and interactions on nuclear activity, we also constructed a suitable control sample of unbarred spiral AGNs without a comp...
Astronomy & Astrophysics, 2019
Here we analyze a sample of close galaxy pairs (relative projected separation < 25 h−1 kpc and... more Here we analyze a sample of close galaxy pairs (relative projected separation < 25 h−1 kpc and relative radial velocities < 350 km s−1) using a weak-lensing analysis based on the Canada-France-Hawaii Telescope Stripe 82 Survey (CS82). We determine halo masses for the total sample of pairs as well as for interacting, red, and higher-luminosity pair subsamples with ∼3σ confidence. The derived lensing signal for the total sample can be fitted either by a Singular Isothermal Sphere (SIS) with σV = 223 ± 24 km s−1 or a Navarro–Frenk–White (NFW) profile with R200 = 0.30 ± 0.03 h−1 Mpc. The pair total masses and total r band luminosities imply an average mass-to-light ratio of ∼200 h M⊙/L⊙. On the other hand, red pairs which include a larger fraction of elliptical galaxies, show a larger mass-to-light ratio of ∼345 h M⊙/L⊙. Derived lensing masses were compared to a proxy of the dynamical mass, obtaining a good correlation. However, there is a large discrepancy between lensing masses ...
Astronomy & Astrophysics, 2018
Aims. With the aim of performing an analysis of the orientations of galaxy pair systems with resp... more Aims. With the aim of performing an analysis of the orientations of galaxy pair systems with respect to the underlying large-scale structure, we study the alignment between the axis connecting the pair galaxies and the host cosmic filament where the pair resides. In addition, we analyze the dependence of the amplitude of the alignment on the morphology of pair members as well as filament properties. Methods. We build a galaxy pair catalog requiring rp < 100 h−1 kpc and ΔV < 500 km s−1 within redshift z < 0.1 from the Sloan Digital Sky Survey (SDSS). We divided the galaxy pair catalog taking into account the morphological classification by defining three pair categories composed by elliptical–elliptical (E–E), elliptical–spiral (E–S) and spiral–spiral (S–S) galaxies. We use a previously defined catalog of filaments obtained from SDSS and we select pairs located closer than 1 h−1 Mpc to the filament spine, which are considered as members of filaments. For these pairs, we calc...
Monthly Notices of the Royal Astronomical Society, 2017
Astronomy & Astrophysics, 2016
Our conception of galaxy evolution inside clusters have recently changed due to an increasing evi... more Our conception of galaxy evolution inside clusters have recently changed due to an increasing evidence suggesting a pre-processing of galaxies at moderate densities. Based on the high frequency of interacting systems found at intermediate densities, we use the SDSS-DR4 data to analyse the role of close galaxy interactions as environmental mechanisms to operate in the evolutionary transformations. We explore the properties of galaxy pairs at different local and global density environments, comparing them with those of isolated galaxies in an unbiased control sample.
Astronomy & Astrophysics, 2014
Astronomy & Astrophysics
Context. The zone of avoidance (ZoA) does not allow for clear optical observations of extragalact... more Context. The zone of avoidance (ZoA) does not allow for clear optical observations of extragalactic sources behind the Milky Way due to the meaningful extinction of the optical emission of these objects. Observations in near-infrared (NIR) wavelengths represent a potential source of astronomical discoveries that support the detection of new galaxies and potentially complete the picture of the large-scale structures in this as-yet poorly explored area of the sky. Aims. Our aim is to decipher the nature of the overdensity located behind the Milky Way in tile b204 of the VISTA Variables in Vía Láctea (VVV) survey. Methods. We studied an area of six arcmin around a galaxy concentration located at l = 354.82° and b = −9.81°. We selected five galaxies, taking into account the source distribution on the sky to optimise the requested time for the observations, and we obtained the spectra with Flamingos 2 long-slit spectrograph at Gemini South 8.1-meter telescope. To identify and characteris...
Symposium - International Astronomical Union, 2004
We analyzed the effects of having a close companion on the star formation activity of galaxies in... more We analyzed the effects of having a close companion on the star formation activity of galaxies in the 8K galaxy pair catalog selected from the 2dFGRS. We found that, statistically, galaxies with rp…
Monthly Notices of the Royal Astronomical Society, 2004
Monthly Notices of the Royal Astronomical Society, 2007
Astronomy & Astrophysics, 2012
Cornell University - arXiv, Oct 28, 2022
Astronomy & Astrophysics, 2021
Context. The extragalactic vision we have through the Milky Way is very unclear. There is signifi... more Context. The extragalactic vision we have through the Milky Way is very unclear. There is significant extinction of the optical emission from objects located in the region called the zone of avoidance (ZOA). NIR wavelengths are less affected by extinction, and therefore the infrared surveys in this zone are a potential source of astronomical discoveries. Nevertheless, these observations need to be compared with cosmological simulations in order to carry out high−accuracy studies. Aims. Our aim is to identify extragalactic sources in the ZOA, using infrared images of the VVV survey. We consider mock galaxy catalogues in order to interpret observational results. Methods. We studied a region of 1.636 square degrees corresponding to the VVV tile b204. Using SExtractor, we analysed photometric data generating a catalogue of extended sources in this area. In order to confirm these sources as galaxy candidates we visually inspected RGB images looking for typical galaxy features. Using 2MAS...
Monthly Notices of the Royal Astronomical Society, 2021
We perform a comparative study of active galactic nuclei (AGNs) in pairs, triplets, and groups. T... more We perform a comparative study of active galactic nuclei (AGNs) in pairs, triplets, and groups. To this end, we use the Duplancic et al. catalogue of small galaxy systems and consider BPT and WHAN diagnostic diagrams to select optical AGNs. Also, we identify mid-IR AGNs by using WISE data. We performed a comparison between the different AGN classification methodologies and study the AGN fraction in pairs, triplets, and groups with four to six members. We also analyse the main properties of Optical and mid-IR AGN hosts and the influence of environment on the active nuclei phenomena in these small galaxy systems. Our results show that, regardless the specifically adopted classification scheme, the fraction of AGN in pairs and triplets is always higher than the corresponding fraction in groups. Moreover, the fraction of powerful AGNs in pair and triplets is about twice the fraction of regular AGNs. We also find a remarkable difference between Optical and mid-IR AGNs in groups, where ho...
Astronomy & Astrophysics, 2021
Aims. We present a statistical analysis of different characteristics of ringed spiral galaxies wi... more Aims. We present a statistical analysis of different characteristics of ringed spiral galaxies with the aim of assessing the effects of rings on disk galaxy properties. Methods. We built a catalog of ringed galaxies from the Sloan Digital Sky Survey Data Release 14 (SDSS-DR14). Via visual inspection of SDSS images, we classified the face-on spiral galaxies brighter than g < 16.0 mag into galaxies with: an inner ring, an outer ring, a nuclear ring, both an inner and an outer ring, and a pseudo-ring. In addition to rings, we recorded morphological types and the existence of bars, lenses, and galaxy pair companions with or without interaction. With the goal of providing an appropriate quantification of the influence of rings on galaxy properties, we also constructed a suitable control sample of non-ringed galaxies with similar redshift, magnitude, morphology, and local density environment distributions to those of ringed ones. Results. We found 1868 ringed galaxies, accounting for 2...
Monthly Notices of the Royal Astronomical Society, 2020
We use SDSS-DR14 to construct a sample of galaxy systems consisting of a central object and two s... more We use SDSS-DR14 to construct a sample of galaxy systems consisting of a central object and two satellites. We adopt projected distance and radial velocity difference criteria and impose an isolation criterion to avoid membership in larger structures. We also classify the interaction between the members of each system through a visual inspection of galaxy images, finding sim80rmpercent{\sim}80{{\ \rm per\ cent}}sim80rmpercent of the systems lack evidence of interactions whilst the remaining sim20rmpercent{\sim}20{{\ \rm per\ cent}}sim20rmpercent involve some kind of interaction, as inferred from their observed distorted morphology. We have considered separately, samples of satellites and central galaxies, and each of these samples were tested against suitable control sets to analyse the results. We find that central galaxies showing signs of interactions present evidence of enhanced star formation activity and younger stellar populations. As a counterpart, satellite samples show these galaxies presenting older stellar populations wit...
Monthly Notices of the Royal Astronomical Society, 2018
Monthly Notices of the Royal Astronomical Society, 2018
Physical Review Letters, 2019
Astronomy & Astrophysics, 2018
Aims. With the aim of performing a suitable comparison of the internal process of galactic bars w... more Aims. With the aim of performing a suitable comparison of the internal process of galactic bars with respect to the external effect of interactions on driving gas toward the inner most region of the galaxies, we explored and compared the efficiency of both mechanisms on central nuclear activity in optically selected active galactic nuclei (AGNs) in spiral galaxies. Methods. We selected homogeneous samples of barred AGNs and active objects residing in pair systems, derived from the Sloan Digital Sky Survey (SDSS). In order to carry out a reliable comparison of both samples (AGNs in barred hosts in isolation and in galaxy pairs), we selected spiral AGN galaxies with similar distributions of redshift, magnitude, stellar mass, color and stellar age population from both catalogs. With the goal of providing an appropriate quantification of the influence of strong bars and interactions on nuclear activity, we also constructed a suitable control sample of unbarred spiral AGNs without a comp...
Astronomy & Astrophysics, 2019
Here we analyze a sample of close galaxy pairs (relative projected separation < 25 h−1 kpc and... more Here we analyze a sample of close galaxy pairs (relative projected separation < 25 h−1 kpc and relative radial velocities < 350 km s−1) using a weak-lensing analysis based on the Canada-France-Hawaii Telescope Stripe 82 Survey (CS82). We determine halo masses for the total sample of pairs as well as for interacting, red, and higher-luminosity pair subsamples with ∼3σ confidence. The derived lensing signal for the total sample can be fitted either by a Singular Isothermal Sphere (SIS) with σV = 223 ± 24 km s−1 or a Navarro–Frenk–White (NFW) profile with R200 = 0.30 ± 0.03 h−1 Mpc. The pair total masses and total r band luminosities imply an average mass-to-light ratio of ∼200 h M⊙/L⊙. On the other hand, red pairs which include a larger fraction of elliptical galaxies, show a larger mass-to-light ratio of ∼345 h M⊙/L⊙. Derived lensing masses were compared to a proxy of the dynamical mass, obtaining a good correlation. However, there is a large discrepancy between lensing masses ...
Astronomy & Astrophysics, 2018
Aims. With the aim of performing an analysis of the orientations of galaxy pair systems with resp... more Aims. With the aim of performing an analysis of the orientations of galaxy pair systems with respect to the underlying large-scale structure, we study the alignment between the axis connecting the pair galaxies and the host cosmic filament where the pair resides. In addition, we analyze the dependence of the amplitude of the alignment on the morphology of pair members as well as filament properties. Methods. We build a galaxy pair catalog requiring rp < 100 h−1 kpc and ΔV < 500 km s−1 within redshift z < 0.1 from the Sloan Digital Sky Survey (SDSS). We divided the galaxy pair catalog taking into account the morphological classification by defining three pair categories composed by elliptical–elliptical (E–E), elliptical–spiral (E–S) and spiral–spiral (S–S) galaxies. We use a previously defined catalog of filaments obtained from SDSS and we select pairs located closer than 1 h−1 Mpc to the filament spine, which are considered as members of filaments. For these pairs, we calc...
Monthly Notices of the Royal Astronomical Society, 2017
Astronomy & Astrophysics, 2016
Our conception of galaxy evolution inside clusters have recently changed due to an increasing evi... more Our conception of galaxy evolution inside clusters have recently changed due to an increasing evidence suggesting a pre-processing of galaxies at moderate densities. Based on the high frequency of interacting systems found at intermediate densities, we use the SDSS-DR4 data to analyse the role of close galaxy interactions as environmental mechanisms to operate in the evolutionary transformations. We explore the properties of galaxy pairs at different local and global density environments, comparing them with those of isolated galaxies in an unbiased control sample.
Astronomy & Astrophysics, 2014