37 research outputs found
Breastfeeding and maternal perceptions of infant sleep, settle and cry patterns in the first 9 months
This study evaluated relationships between maternal perceptions of infant sleep, settling and crying patterns and breastfeeding. A prospective observational study of 91 mothers of healthy, term infants was conducted with follow ups over 9 months after discharge from a Western Australian maternity hospital. Feeding information, sleep, settle and cry behaviours, maternal bother at infant behaviours and confidence were measured using the Sleep and Settle Questionnaire. Breastfeeding confidence was measured using the Breastfeeding Self-Efficacy Scale—Short Form. Questionnaires were administered at 2 and 6 weeks, 3, 6 and 9 months. Linear mixed models were used to assess associations between maternal bother, feeding method and infant characteristics. The feeding method was not associated with maternal bother, and cessation of breastfeeding did not result in a change in bother scores (p = 0.34). Duration of infant crying in the day, evening and night, frequency of night waking and duration of settling to sleep in the day were associated with increased bother scores. Higher breastfeeding self-efficacy and maternal confidence were associated with lower bother scores (both p < 0.01). Maternal bother is associated with infant behaviours that require parental input, but not breastfeeding status. Resources that address parental expectations regarding infant sleep while providing strategies to support maternal wellbeing and breastfeeding are needed
Gemini Near Infrared Spectrograph - Distant Quasar Survey: Prescriptions for Calibrating UV-Based Estimates of Supermassive Black Hole Masses in High-Redshift Quasars
The most reliable single-epoch supermassive black hole mass ()
estimates in quasars are obtained by using the velocity widths of
low-ionization emission lines, typically the H line.
Unfortunately, this line is redshifted out of the optical band at ,
leaving estimates to rely on proxy rest-frame ultraviolet (UV)
emission lines, such as C IV or Mg II , which
contain intrinsic challenges when measuring, resulting in uncertain estimates. In this work, we aim at correcting estimates
derived from the C IV and Mg II emission lines based on estimates derived from
the H emission line. We find that employing the equivalent width of C IV
in deriving estimates based on Mg II and C IV provides values that
are closest to those obtained from H. We also provide prescriptions to
estimate values when only C IV, only Mg II, and both C IV and Mg
II are measurable. We find that utilizing both emission lines, where available,
reduces the scatter of UV-based estimates by when
compared to previous studies. Lastly, we discuss the potential of our
prescriptions to provide more accurate and precise estimates of
given a much larger sample of quasars at , where
both Mg II and H can be measured in the same near-infrared spectrum.Comment: 19 pages (AASTeX 6.3.1), 9 figures, accepted for publication in Ap
Placing high-redshift quasars in perspective: A catalog of spectroscopic properties from the gemini near infrared spectrograph-distant quasar survey
We present spectroscopic measurements for 226 sources from the Gemini Near Infrared Spectrograph-Distant Quasar Survey (GNIRS-DQS). Being the largest uniform, homogeneous survey of its kind, it represents a fluxlimited sample (mi≤19.0 mag, H≤16.5 mag) of Sloan Digital Sky Survey (SDSS) quasars at 1.5 ≤ z ≤ 3.5 with a monochromatic luminosity (λLλ) at 5100 Å in the range of 1044-1046 erg s-1. A combination of the GNIRS and SDSS spectra covers principal quasar diagnostic features, chiefly the C IV λ1549, Mg II λλ2798, 2803, Hβ λ4861, and [O III] λλ4959, 5007 emission lines, in each source. The spectral inventory will be utilized primarily to develop prescriptions for obtaining more accurate and precise redshifts, black hole masses, and accretion rates for all quasars. Additionally, the measurements will facilitate an understanding of the dependence of rest-frame ultraviolet-optical spectral properties of quasars on redshift, luminosity, and Eddington ratio, and test whether the physical properties of the quasar central engine evolve over cosmic time.Fil: Matthews, Brandon M.. University of North Texas; Estados UnidosFil: Shemmer, Ohad. University of North Texas; Estados UnidosFil: Dix, Cooper. University of North Texas; Estados UnidosFil: Brotherton, Michael S.. University of Wyoming; Estados UnidosFil: Myers, Adam D.. University of Wyoming; Estados UnidosFil: Andruchow, Ileana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Brandt, W.N.. State University of Pennsylvania; Estados UnidosFil: Ferrero, Gabriel A.. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Gallagher, S.C.. The University Of Western Ontario; CanadáFil: Green, Richard. University of Arizona; Estados UnidosFil: Lira, Paulina. Universidad de Chile.; ChileFil: Plotkin, Richard M.. University of Nevada. Deparment of Physics; Estados UnidosFil: Richards, Gordon T.. Drexel University; Estados UnidosFil: Runnoe, Jessie C.. Vanderbilt University; Estados UnidosFil: Schneider, Donald P.. State University of Pennsylvania; Estados UnidosFil: Shen, Yue. University of Illinois at Urbana; Estados UnidosFil: Strauss, Michael A.. University of Princeton; Estados UnidosFil: Wills, Beverley J.. University of Texas at Austin; Estados Unido
Gemini Near Infrared Spectrograph -- Distant Quasar Survey: Augmented Spectroscopic Catalog and a Prescription for Correcting UV-Based Quasar Redshifts
Quasars at most often have redshifts measured from rest-frame
ultraviolet emission lines. One of the most common such lines, C IV
, shows blueshifts up to , and in
rare cases even higher. This blueshifting results in highly uncertain redshifts
when compared to redshift determinations from rest-frame optical emission
lines, e.g., from the narrow [O III] feature. We present
spectroscopic measurements for 260 sources at
having
mag from the Gemini Near Infrared
Spectrograph - Distant Quasar Survey (GNIRS-DQS) catalog, augmenting the
previous iteration which contained 226 of the 260 sources whose measurements
are improved upon in this work. We obtain reliable systemic redshifts based on
[O III] for a subset of 121 sources which we use to calibrate
prescriptions for correcting UV-based redshifts. These prescriptions are based
on a regression analysis involving C IV full-width-at-half-maximum intensity
and equivalent width, along with the UV continuum luminosity at a rest-frame
wavelength of 1350 A. Applying these corrections can improve the accuracy and
the precision in the C IV-based redshift by up to
and , respectively, which correspond to
Mpc and Mpc in comoving distance at . Our prescriptions
also improve the accuracy of the best available multi-feature redshift
determination algorithm by , indicating that the
spectroscopic properties of the C IV emission line can provide robust redshift
estimates for high-redshift quasars. We discuss the prospects of our
prescriptions for cosmological and quasar studies utilizing upcoming large
spectroscopic surveys.Comment: 20 pages (AASTeX 6.3.1), 8 figures, accepted for publication in Ap
Shedding New Light on Weak Emission-Line Quasars in the C-H Parameter Space
Weak emission-line quasars (WLQs) are a subset of Type 1 quasars that exhibit
extremely weak LyN V 1240 and/or C IV 1549 emission
lines. We investigate the relationship between emission-line properties and
accretion rate for a sample of 230 `ordinary' Type 1 quasars and 18 WLQs at and that have rest-frame ultraviolet and optical
spectral measurements. We apply a correction to the H-based black-hole
mass () estimates of these quasars using the strength of the
optical Fe II emission. We confirm previous findings that WLQs'
values are overestimated by up to an order of magnitude using the traditional
broad emission-line region size-luminosity relation. With this
correction, we find a significant correlation between H-based Eddington
luminosity ratios and a combination of the rest-frame C IV equivalent width and
C IV blueshift with respect to the systemic redshift. This correlation holds
for both ordinary quasars and WLQs, which suggests that the two-dimensional C
IV parameter space can serve as an indicator of accretion rate in all Type 1
quasars across a wide range of spectral properties.Comment: 17 pages (AASTeX 6.3.1), 5 figures, accepted for publication in Ap
Intraseasonal oscillations in 15 atmospheric general circulation models: results from an AMIP diagnostic subproject
The ability of 15 atmospheric GCM models (AGCM) to simulate the tropical intraseasonal oscillation has been studied as part of AMIP. Time series of the daily upper tropospheric velocity potential and zonal wind, averaged over the equatorial belt, were provided from each AGCM simulation. These data were analyzed using a variety of techniques such as time filtering and space-time spectral analysis to identify eastward and westward propagating waves. The results have been compared with an identical assessment of ECMWF analyses for the period 1982-1991. The models display a wide range of skill in simulating the intraseasonal oscillation. Most models show evidence of an eastward propagating anomaly in the velocity potential field, although in some models there is a greater tendency for a standing oscillation, and in one or two the field is rather chaotic with no preferred direction of propagation. Where a model has a clear eastward propagating signal, typical periodicities seem quite reasonable although there is a tendency for the models to simulate shorter periods than in the ECMWF analyses, where it is near 50 days. The results of the space-time spectral analysis have shown that no model has captured the dominance of the intraseasonal oscillation found in the analyses. Several models have peaks at intraseasonal time scales, but nearly all have relatively more power at higher frequencies
Placing High-Redshift Quasars in Perspective: a Catalog of Spectroscopic Properties from the Gemini Near Infrared Spectrograph - Distant Quasar Survey
We present spectroscopic measurements for 226 sources from the Gemini Near Infrared Spectrograph - Distant Quasar Survey (GNIRS-DQS). Being the largest uniform, homogeneous survey of its kind, it represents a flux-limited sample (mi . 19.0 mag, H . 16.5 mag) of Sloan Digital Sky Survey (SDSS) quasars at 1.5 . z . 3.5 with a monochromatic luminosity (λLλ) at 5100 ˚A in the range of 1044 − 1046 erg s−1 . A combination of the GNIRS and SDSS spectra covers principal quasar diagnostic features, chiefly the C iv λ1549, Mg ii λλ2798, 2803, Hβ λ4861, and [O iii] λλ4959, 5007 emission lines, in each source. The spectral inventory will be utilized primarily to develop prescriptions for obtaining more accurate and precise redshifts, black hole masses, and accretion rates for all quasars. Additionally, the measurements will facilitate an understanding of the dependence of rest-frame ultraviolet-optical spectral properties of quasars on redshift, luminosity, and Eddington ratio, and test whether the physical properties of the quasar central engine evolve over cosmic time.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat