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Word list-learning tasks are commonly used to evaluate auditory-verbal learning and memory. However, different frequencies of word usage, subtle meaning nuances, unique word phonology, and different preexisting associations among words make translation across languages difficult. We administered lists of consonant-vowel-consonant (CVC) nonword trigrams to independent American and Italian young adult samples. We evaluated whether an auditory list-learning task using CVC nonword trigrams instead of words could be applied cross-culturally to evaluate similar learning and associative memory processes.
Participants and Methods:
Seventy-five native English-speaking (USA) and 104 native Italian-speaking (Italy) university students were administered 15-item lists of CVC trigrams using the Rey Auditory Verbal Learning Test paradigm with five study-test trials, an interference trial, and short- and long-term delayed recall. Bayesian t tests and mixed-design ANOVAs contrasted the primary learning indexes across the two samples and biological sex.
Performance was comparable between nationalities on all primary memory indices except the interference trial (List B), where the Italian group recalled approximately one item more than the American sample. For both nationalities, recall increased across the five learning trials and declined significantly on the postinterference trial, demonstrating susceptibility to retroactive interference. No effects of sex, age, vocabulary, or depressive symptoms were observed.
Using lists of unfamiliar nonword CVC trigrams, Italian and American younger adults showed a similar performance pattern across immediate and delayed recall trials. Whereas word list-learning performance is typically affected by cultural, demographic, mood, and cognitive factors, this trigram list-learning task does not show such effects, demonstrating its utility for cross-cultural memory assessment.
We describe the scientific goals and survey design of the First Large Absorption Survey in H i (FLASH), a wide field survey for 21-cm line absorption in neutral atomic hydrogen (H i) at intermediate cosmological redshifts. FLASH will be carried out with the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope and is planned to cover the sky south of
$\delta \approx +40\,\deg$
at frequencies between 711.5 and 999.5 MHz. At redshifts between
$z = 0.4$
(look-back times of 4 – 8 Gyr), the H i content of the Universe has been poorly explored due to the difficulty of carrying out radio surveys for faint 21-cm line emission and, at ultra-violet wavelengths, space-borne searches for Damped Lyman-
absorption in quasar spectra. The ASKAP wide field of view and large spectral bandwidth, in combination with a radio-quiet site, will enable a search for absorption lines in the radio spectra of bright continuum sources over 80% of the sky. This survey is expected to detect at least several hundred intervening 21-cm absorbers and will produce an H i-absorption-selected catalogue of galaxies rich in cool, star-forming gas, some of which may be concealed from optical surveys. Likewise, at least several hundred associated 21-cm absorbers are expected to be detected within the host galaxies of radio sources at
$0.4 < z < 1.0$
, providing valuable kinematical information for models of gas accretion and jet-driven feedback in radio-loud active galactic nuclei. FLASH will also detect OH 18-cm absorbers in diffuse molecular gas, megamaser OH emission, radio recombination lines, and stacked H i emission.
We present a new method to combine cold gas kinematics with the stellar kinematics modelled with the Schwarzschild orbit-superposition technique, and its application to the lenticular galaxy NGC 2974. The combination of stellar and cold gas kinematics significantly improves the constraints on the measured dark matter profile: assuming a generalised NFW halo profile, we find a cuspy inner halo slope for NGC 2974.
We present HI images for the dust-lane elliptical galaxy NGC 5266. This galaxy contains more than 1010M☉ of HI and our data show that the neutral hydrogen extends to ∼8 arcmin each side of the nucleus, or eight times the optical half-light radius Re. Surprisingly, the outer HI gas extends almost orthogonally to the optical dust lane. The overall HI kinematics can be successfully modelled by assuming that the gas hes in two orthogonal planes—in the plane of the dust lane in the central parts and perpendicular to this in the outer regions. The large amount of neutral gas observed and the HI morphology suggest that this object may have formed from the merger of two gas rich spiral galaxies. If so, it probably represents a relatively old merger remnant since most of the HI appears settled. The mass-to-light ratio has also been derived, with evidence for a dark matter halo around this galaxy.
Recent observations with the Australia Telescope Compact Array show that the elliptical galaxy NGC 5266 has a disk of neutral hydrogen extending to almost 10Re. This HI disk lies along the galaxy’s major axis, at right angles to the inner minor-axis dust lane. The geometry and kinematics of the gas will allow us to determine both the intrinsic shape of the stellar galaxy and the mass distribution. The mass-to-light ratio M/LB rises from about 2 in the central regions to ~12 at 9Re (H0 = 50km s−1 Mpc−1).
Radio, optical and X-ray observations of a complete flux-limited sample of southern bright radio sources have been analysed to investigate beaming and orientation effects in the different wavebands. We conclude that, in addition to beamed optical and radio components, there is evidence for anisotropic X-ray emission.
The tight correlations observed between galaxies and their SMBH provides compelling evidence that the evolution of the galaxy and its central black hole are strongly linked. This is generally attributed to feedback mechanisms which, according to simulations, often take the form of outflows of gas, quenching star formation in the host galaxy and halting accretion onto the central black hole. While there are a number of plausible ways that outflows could be produced, recent results have shown that in some cases radio jets could be responsible for driving fast outflows of gas. One such example is seen in the nearby radio galaxy 3C293. In this talk I will present results from JVLA radio observations where we detect fast outflows (~1200 km/s) of neutral gas which are being driven by the radio-jet approximately 0.5 kpc from the central core, providing direct evidence for jet-ISM interaction. This is accompanied with recent IFU observations showing that ionised gas outflows are also being driven by the radio jet. Pinpointing the location of these outflows enables us to derive crucial parameters, such as the mass outflow rates and kinetic energy involved, which we can compare to predictions from galaxy evolution simulations.
We are performing a multi-frequency radio analysis of a well-known deep field: the Lockman Hole, which is one of the best studied sky regions in different wavebands. This will provide us with important complementary data (for example redshifts) to the radio data, allowing us to characterize the physical and evolutionary properties of the various classes of sources composing the faint radio population. LOFAR imaging of the Lockman Hole can play an important role in this project, allowing, for the very first time, to observe the sub-mJy source population at very low frequencies (30-200 MHz), where self-absorption phenomena are expected to be very important. Here we present some preliminary results.
We present new Karl G. Jansky Very Large Array (VLA) Hi absorption and Very Long Baseline Array (VLBA) continuum observations of the active galactic nucleus (AGN)-driven molecular outflow candidate NGC 1266. Although other well-known systems with molecular outflows may be driven by star formation in a central molecular disk, the molecular mass outflow rate reported in Alatalo et al. (2011) in NGC 1266 of 13 M⊙ year−1 exceeds star formation rate estimates from a variety of tracers. This suggests that an additional energy source, such as an AGN, may play a significant role in powering the outflow. Our high spatial resolution Hi absorption data reveal compact absorption against the radio continuum core co-located with the putative AGN, and the presence of a blueshifted spectral component re-affirms that gas is indeed flowing out of the system. Our VLBA observations at 1.65 GHz reveal one continuum source within the densest portion of the molecular gas, with a diameter d < 8 mas (1.2 pc), a radio power Prad = 1.48 × 1020 W Hz−1, and a brightness temperature Tb > 1.5 × 107 K that is most consistent with an AGN origin. The radio continuum energetics implied by the compact VLBA source, as well as archival VLA continuum observations at lower spatial resolution, further support the possibility that the AGN in NGC 1266 could be driving the molecular outflow. These findings suggest that even low-level AGNs, with supermassive black hole masses similar to Sgr A*, may be able to launch massive outflows in their host galaxies.
We present high resolution spectra (0.7 Å/pix) of the GPS source 4C 12.50 with large spectral coverage (˜4500 Å) taken with the 4.2 m William Herschel Telescope, La Palma. The slit was aligned along PA 160° to include the nucleus and emission line region to the NW. An asymmetric halo extending 20 kpc NW and 12 kpc SE from the nucleus is clearly seen. At the position of the nucleus we observe unusually broad forbidden emission line components (broadest component: FWHM ˜ 2000 km s−1), blue shifted by up to 2000 km s−1 with respect to the halo of the galaxy and HI absorption. We interpret this as material in outflow. We measure E(B–V) = 1.44 for the broadest, most kinematically disturbed component, corresponding to an actual Hβ flux 130 times brighter than that measured. We calculate an upper limit for the mass of the line emitting gas of order 106 M⊙ for both the intermediate and broad components. Our results are consistent with 4C 12.50 being a young radio source.
We have obtained long slit spectra of 3C 67 and 3C 277.1 with the HST/STIS spectrograph. We present our preliminary results on the diagnostic emission line ratios along the radio source axes in 3C 67 and 3C 277.1.
The study of both neutral and ionised gas in young radio sources is providing key information on the effect the radio plasma has on the ISM of these objects. We present results obtained for the compact radio sources PKS 1549–79, 4C 12.50 and PKS 1814–63 and for the intermediate-size radio galaxy 3C 459. At least in the first two, low ionisation optical emission lines and HI absorption appear to be associated with the extended, but relatively quiescent, dusty cocoon surrounding the nucleus. The [OIII] lines are, on the other hand, mostly associated with the region of interaction between the radio plasma and the ISM, indicating a fast outflow from the centre. A case of fast outflow (up to ∼1000 km s-1) is also observed in HI in the radio source 4C 12.50. As the radio source evolves, any obscuring material along the radio axis is swept aside until, eventually, cavities (of the same kind as observed e.g. in Cygnus A) are hollowed out on either side of the nucleus. We may witness this phase in the evolution of a radio source in the radio galaxy 3C 459.
We have obtained HST/STIS long slit spectroscopy of the aligned emission line nebulae in three compact steep spectrum (CSS) radio sources — 3C 67, 3C 277.1, and 3C 303.1. We find systematic offsets (˜300–500 kms) of the emission line velocities on one or both sides of the radio sources. We also see evidence for broad lines (FWHM ˜500 kms) and complex emission line profiles. In 3C 303.1 the data are consistent with multiple components and possibly split lines. The amplitude of the velocity variations is not so large as to exclude gravitationally-induced motions. However, the complex kinematics, the lack of a signature of Keplerian rotation, and the association of the velocity variations with the radio lobes are consistent with the observed ˜300–500 kms velocities being driven by the expansion of the radio source. Acceleration of the clouds by the bow shock is plausible given the estimated densities in the clouds and the velocities observed in the much smaller compact symmetric objects and with expansion velocities estimated from spectral ageing. This conclusion is unchanged if we consider the scenario in which the cloud acceleration is dominated by the post bow shock flow.
According to a popular scenario supported by numerical models, the mass assembly and growth of massive galaxies, in particular the Early-Type Galaxies (ETGs), is, below a redshift of 1, mainly due to the accretion of multiple gas–poor satellites. In order to get observational evidence of the role played by minor dry mergers, we are obtaining extremely deep optical images of a complete volume limited sample of nearby ETGs. These observations, done with the CFHT as part of the ATLAS3D, NGVS and MATLAS projects, reach a stunning 28.5 – 29 mag.arcsec−2 surface brightness limit in the g' band. They allow us to detect the relics of past collisions such as faint stellar tidal tails as well as the very extended stellar halos which keep the memory of the last episodes of galactic accretion. Images and preliminary results from this on-going survey are presented, in particular a possible correlation between the fine structure index (which parametrizes the amount of tidal perturbation) of the ETGs, their stellar mass, effective radius and gas content.
We detail the rich molecular story of NGC 1266, its serendipitous discovery within the ATLAS3D survey (Cappellari et al. 2011) and how it plays host to an AGN-driven molecular outflow, potentially quenching all of its star formation (SF) within the next 100 Myr. While major mergers appear to play a role in instigating outflows in other systems, deep imaging of NGC 1266 as well as stellar kinematic observations from SAURON, have failed to provide evidence that NGC 1266 has recently been involved in a major interaction. The molecular gas and the instantaneous SF tracers indicate that the current sites of star formation are located in a hypercompact disk within 200 pc of the nucleus (Fig. 1; SF rate ≈ 2 M⊙ yr−1). On the other hand, tracers of recent star formation, such as the Hβ absorption map from SAURON and stellar population analysis show that the young stars are distributed throughout a larger area of the galaxy than current star formation. As the AGN at the center of NGC 1266 continues to drive cold gas out of the galaxy, we expect star formation rates to decline as the star formation is ultimately quenched. Thus, NGC 1266 is in the midst of a key portion of its evolution and continued studies of this unique galaxy may help improve our understanding of how galaxies transition from the blue to the red sequence (Alatalo et al. 2011).
NGC 1266 is a nearby field galaxy observed as part of the ATLAS3D survey (Cappellari et al. 2011). NGC 1266 has been shown to host a compact (< 200 pc) molecular disk and a mass-loaded molecular outflow driven by the AGN (Alatalo et al. 2011). Very Long Basline Array (VLBA) observations at 1.65 GHz revealed a compact (diameter < 1.2 pc), high brightness temperature continuum source most consistent with a low-level AGN origin. The VLBA continuum source is positioned at the center of the molecular disk and may be responsible for the expulsion of molecular gas in NGC 1266. Thus, the candidate AGN-driven molecular outflow in NGC 1266 supports the picture in which AGNs do play a significant role in the quenching of star formation and ultimately the evolution of the red sequence of galaxies.
In around ≈25% of early-type galaxies (ETGs) UV emission from young stellar populations is present. Molecular gas reservoirs have been detected in these systems (e.g. Young et al. (2011), providing the fuel for this residual star-formation. The environment in which this molecular gas is found is quite different than that in spiral galaxies however, with harsher radiation fields, deeper potentials and high metallicity and alpha-element abundances. Here we report on one element of our multi-faceted programme to understand the similarities and differences between the gas reservoirs in spirals and ETGs. We use spatially resolved observations from the CARMA mm-wave interferometer to investigate the size of the molecular reservoirs in the the CO-rich ATLAS3D ETGs (survey described in Alatalo et al. 2012, submitted). We find that the molecular gas extent is smaller in absolute terms in ETGs than in late-type galaxies, but that the size distributions are similar once scaled by the galaxies optical/stellar characteristic scale-lengths (Fig 1, left). Amongst ETGs, we find that the extent of the molecular gas is independent of the kinematic misalignment, despite the many reasons why misaligned gas might have a smaller extent. The extent of the molecular gas does depend on environment, with Virgo cluster ETGs having less extended molecular gas reservoirs (Fig 1, right). Whatever the cause, this further emphases that cluster ETGs follow different evolutionary pathways from those in the field. Full details of this work will be presented in Davis et al. (2012), submitted.
Recently, massive early-type galaxies have shed their red-and-dead moniker, thanks to the discovery that many host residual star formation. As part of the ATLAS-3D project, we have conducted a complete, volume-limited survey of the molecular gas in 260 local early-type galaxies with the IRAM-30m telescope and the CARMA interferometer, in an attempt to understand the fuel powering this star formation. We find that around 22% of early-type galaxies in the local volume host molecular gas reservoirs. This detection rate is independent of galaxy luminosity and environment. Here we focus on how kinematic misalignment measurements and gas-to-dust ratios can be used to put constraints on the origin of the cold ISM in these systems. The origin of the cold ISM seems to depend strongly on environment, with misaligned, dust poor gas (indicative of externally acquired material) being common in the field but completely absent in rich groups and in the Virgo cluster. Very massive galaxies also appear to be devoid of accreted gas. This suggests that in the field mergers and/or cold gas accretion dominate the gas supply, while in clusters internal secular processes become more important. This implies that environment has a strong impact on the cold gas properties of ETGs.
Excluding those unsettled systems undergoing mergers, bright galaxies come in two flavours: with and without discs. In this work we look for photometric evidence for presence of discs and compare it with kinematic results of the ATLAS3D survey (Cappellari et al. 2011). We fit a Sérsic (1968) function to azimuthally averaged light profiles of ATLAS3D galaxies to derive single component fits and, subsequently, we fit a combination of the Sérsic function (free index n) and an exponential function (n=1) with the purpose of decomposing the light profiles into “bulge” and “disc” components (B+D model) of all non-barred sample galaxies. We compare the residuals of the B+D models with those of the single Sérsic fits and select the B+D model as preferred only when the improvement is substantial and there are no correlations within residuals. We find that the high angular momentum objects (fast rotators) are disc dominated systems with bulges of typically low n (when their light profiles can be decomposed) or are best represented with a single Sérsic function with a low Sérsic index (n<3). Single component systems with large Sérsic indices are characteristic of low angular momentum objects (slow rotators).
We have carried out 1mm/3mm continuum and 12CO(2−1) line high resolution observations to identify the footprints of AGN feedback on 3C 236. The CO emission comes from a spatially resolved disk characterized by a regular rotating pattern. Within the limits imposed by the sensitivity and velocity coverage of our data, we do not detect any outflow signatures in the cold molecular gas. Re-inspection of optical and IR spectra, shows the presence of a previously unknown ionized gas outflow. The star-formation efficiency in 3C 236, is consistent with the value measured in normal galaxies, which follow the canonical Kennicutt-Schmidt law. This result, confirmed to hold in other young radio sources examined in this work, is in stark contrast with the factor of 10–50 lower SFE that has been claimed to characterize evolved powerful radio galaxies. The recent reactivation of the AGN in 3C 236 is a likely explanation for the early evolutionary status of its molecular disk.