Browsing by Author "Barcos-Munoz, L."

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    A 33GHz Survey of Local Major Mergers: Estimating the Sizes of the Energetically Dominant Regions from High-resolution Measurements of the Radio Continuum
    (2017) Barcos-Munoz, L.; Leroy, A. K.; Evans, A. S.; Condon, J.; Privon, G. C.; Thompson, T. A.; Armus, L.; Diaz-Santos, T.; Mazzarella, J. M.; Meier, D. S.; Momjian, E.; Murphy, E. J.; Ott, J.; Sanders, D. B.; Schinnerer, E.; Stierwalt, S.; Surace, J. A.; Walter, F.
    We present Very Large Array observations of the 33 GHz radio continuum emission from 22 local ultraluminous and luminous infrared (IR) galaxies (U/LIRGs). These observations have spatial (angular) resolutions of 30-720 pc (0.'' 07-0.'' 67) in a part of the spectrum that is likely to be optically thin. This allows us to estimate the size of the energetically dominant regions. We find half-light radii from 30 pc to 1.7 kpc. The 33 GHz flux density correlates well with the IR emission, and we take these sizes as indicative of the size of the region that produces most of the energy. Combining our 33 GHz sizes with unresolved measurements, we estimate the IR luminosity and star formation rate per area and the molecular gas surface and volume densities. These quantities span a wide range (4 dex) and include some of the highest values measured for any galaxy (e.g., Sigma(33 GHz)(SFR) <= 10(4.1) M-circle dot yr(-1) kpc(-2)) at least 13 sources appear Compton thick (N-H(33 GHz) >= 10(24) cm(-2)). Consistent with previous work, contrasting these data with observations of normal disk galaxies suggests a nonlinear and likely multivalued relation between star formation rate and molecular gas surface density, though this result depends on the adopted CO-to-H-2 conversion factor and the assumption that our 33 GHz sizes apply to the gas. Eleven sources appear to exceed the luminosity surface density predicted for starbursts supported by radiation pressure and supernova feedback; however, we note the need for more detailed observations of the inner disk structure. U/LIRGs with higher surface brightness exhibit stronger [C II] 158 mu m deficits, consistent with the suggestion that high energy densities drive this phenomenon.
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    Molecular gas and dust properties of galaxies from the Great Observatories All-sky LIRG Survey
    (2019) Herrero-Illana, R.; Privon, G. C.; Evans, A. S.; Diaz-Santos, T.; Perez-Torres, M. A.; Alberdi, A.; Iwasawa, K.; Armus, L.; Aalto, S.; Mazzarella, J.; Chu, J.; Sanders, D. B.; Barcos-Munoz, L.; Charmandaris, V; Linden, S. T.; Yoon, I; Frayer, D. T.; Inami, H.; Kim, D-C; Borish, H. J.; Conway, J.; Murphy, E. J.; Song, Y.; Stierwalt, S.; Surace, J.
    We present IRAM-30 m Telescope (CO)-C-12 and (CO)-C-13 observations of a sample of 55 luminous and ultraluminous infrared galaxies (LIRGs and ULIRGs) in the local universe. This sample is a subset of the Great Observatory All-Sky LIRG Survey (GOALS), for which we use ancillary multi-wavelength data to better understand their interstellar medium and star formation properties. Fifty-three (96%) of the galaxies are detected in (CO)-C-12, and 29 (52%) are also detected in (CO)-C-13 above a 3 sigma level. The median full width at zero intensity (FWZI) velocity of the CO line emission is 661 km s(-1), and similar to 54% of the galaxies show a multi-peak CO profile. Herschel photometric data is used to construct the far-IR spectral energy distribution of each galaxy, which are fit with a modified blackbody model that allows us to derive dust temperatures and masses, and infrared luminosities. We make the assumption that the gas-to-dust mass ratio of (U)LIRGs is comparable to local spiral galaxies with a similar stellar mass (i.e., gas/dust of mergers is comparable to their progenitors) to derive a CO-to-H-2 conversion factor of = 1.8(-0.8)(+1.3) M-circle dot (K km s(-1) pc(2))(-1); such a value is comparable to that derived for (U)LIRGs based on dynamical mass arguments. We derive gas depletion times of 400 600 Myr for the (U)LIRGs, compared to the 1.3 Gyr for local spiral galaxies. Finally, we re-examine the relationship between the (CO)-C-12/(CO)-C-13 ratio and dust temperature, confirming a transition to elevated ratios in warmer systems.
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    The ALMA-CRISTAL survey Discovery of a 15 kpc-long gas plume in a z=4.54 Lyman-α blob
    (2024) Solimano, M.; Gonzalez-Lopez, J.; Aravena, M.; Herrera-Camus, R.; De Looze, I.; Schreiber, N. M. Foerster; Spilker, J.; Tadaki, K.; Assef, R. J.; Barcos-Munoz, L.; Davies, R. L.; Diaz-Santos, T.; Ferrara, A.; Fisher, D. B.; Guaita, L.; Ikeda, R.; Johnston, E. J.; Lutz, D.; Mitsuhashi, I.; Moya-Sierralta, C.; Relano, M.; Naab, T.; Posses, A. C.; Telikova, K.; Uebler, H.; van der Giessen, S.; Veilleux, S.; Villanueva, V.
    Massive star-forming galaxies in the high-redshift universe host large reservoirs of cold gas in their circumgalactic medium (CGM). Traditionally, these reservoirs have been linked to diffuse H I Lyman-alpha (Ly alpha) emission extending beyond approximate to 10 kpc scales. In recent years, millimeter and submillimeter observations have started to identify even colder gas in the CGM through molecular and/or atomic tracers such as the [C II] 158 mu m transition. In this context, we studied the well-known J1000+0234 system at z = 4.54 that hosts a massive dusty star-forming galaxy (DSFG), a UV-bright companion, and a Ly alpha blob. We combined new ALMA [C II] line observations taken by the CRISTAL survey with data from previous programs targeting the J1000+0234 system, and achieved a deep view into a DSFG and its rich environment at a 0 ''. 2 = 1.3 kpc resolution. We identified an elongated [C II]-emitting structure with a projected size of 15 kpc stemming from the bright DSFG at the center of the field, with no clear counterpart at any other wavelength. The plume is oriented approximate to 40 degrees away from the minor axis of the DSFG, and shows significant spatial variation of its spectral parameters. In particular, the [C II] emission shifts from 180 km s(-1 )to 400 km s(-1) between the bottom and top of the plume, relative to the DSFG's systemic velocity. At the same time, the line width starts at 400 - 600 km s(-1) but narrows down to 190 km s(-1) at the top end of the plume. We discuss four possible scenarios to interpret the [C II] plume: a conical outflow, a cold accretion stream, ram pressure stripping, and gravitational interactions. While we cannot strongly rule out any of these with the available data, we disfavor the ram pressure stripping scenario due to the requirement of special hydrodynamic conditions.
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    The ALMA-CRISTAL survey: Dust temperature and physical conditions of the interstellar medium in a typical galaxy at z=5.66
    (2024) Villanueva, V.; Herrera-Camus, R.; Gonzalez-Lopez, J.; Aravena, M.; Assef, R. J.; Baeza-Garay, M.; Barcos-Munoz, L.; Bovino, S.; Bowler, R. A. A.; da Cunha, E.; De Looze, I.; Diaz-Santos, T.; Ferrara, A.; Foerster Schreiber, N. M.; Algera, H.; Ikeda, R.; Killi, M.; Mitsuhashi, I.; Naab, T.; Relano, M.; Spilker, J.; Solimano, M.; Palla, M.; Price, S. H.; Posses, A.; Tadaki, K.; Telikova, K.; Ubler, H.
    We present new lambda(rest) = 77 mu m dust continuum observations from the Atacama Large Millimeter/submillimeter Array of HZ10 (CRISTAL-22). This dusty main sequence galaxy at z = 5.66 was observed as part of the [CII] Resolved Ism in STar-forming Alma Large program (CRISTAL). The high angular resolution of the ALMA Band 7 and new Band 9 data (similar to 0 ''.4) reveals the complex structure of HZ10, which comprises two main components (HZ10-C and HZ10-W), along with a bridge-like dusty emission between them (i.e., "the bridge"). Using a modified blackbody function to model the dust spectral energy distribution (SED), we constrained the physical conditions of the interstellar medium (ISM) and its variations among the different components identified in HZ10. We find that HZ10-W (the more UV-obscured component) has an SED dust temperature of T-SED similar to 51.2 +/- 13.1 K; this was found to be similar to 5 K higher (which is statistically insignificant; i.e., less than 1 sigma) than that of the central component and previous global estimations for HZ10. Our new ALMA data allow us to reduce the uncertainties of global T-SED measurements by a factor of similar to 2.3, compared to previous studies. The HZ10 components have [CII]-to-far-infrared (FIR) luminosity ratios and FIR surface densities values that are consistent with local starburst galaxies. However, HZ10-W shows a lower [CII]/FIR ratio compared to the other two components (albeit still within the uncertainties), which may suggest a harder radiation field destroying polycyclic aromatic hydrocarbon associated with [CII] emission (e.g., active galactic nuclei or young stellar populations). While HZ10-C appears to follow the tight IRX-beta(UV) relation seen in local UV-selected starburst galaxies and high-z star-forming galaxies, we find that both HZ10-W and the bridge depart from this relation and are well described by dust-screen models with holes in front of a hard UV radiation field. This suggests that the UV emission, which is likely coming from young stellar populations, is strongly attenuated in the "dustier" components of the HZ10 system.