The impact of the FMR and starburst galaxies on the (low-metallicity) cosmic star formation history

The question how much star formation is occurring at low metallicity throughout the cosmic history appears crucial for the discussion of the origin of various energetic transients, and possibly - double black hole mergers. We revisit the observation-based distribution of birth metallicities of stars (fSFR(Z,z)), focusing on several factors that strongly affect its low metallicity part: (i) the method used to describe the metallicity distribution of galaxies (redshift-dependent mass metallicity relation - MZR, or redshift-invariant fundamental metallicity relation - FMR), (ii) the contribution of starburst galaxies and (iii) the slope of the MZR. We empirically construct the FMR based on the low-redshift scaling relations, which allows us to capture the systematic differences in the relation caused by the choice of metallicity and star formation rate (SFR) determination techniques and discuss the related fSFR(Z,z) uncertainty. We indicate factors that dominate the fSFR(Z,z) uncertainty in different metallicity and redshift regimes. The low metallicity part of the distribution is poorly constrained even at low redshifts (even a factor of ∼200 difference between the model variations) The non-evolving FMR implies a much shallower metallicity evolution than the extrapolated MZR, however, its effect on the low metallicity part of the fSFR(Z,z) is counterbalanced by the contribution of starbursts (assuming that they follow the FMR). A non-negligible fraction of starbursts in our model may be necessary to satisfy the recent high-redshift SFR density constraints.

Morality Plays

The “morality play” is one of the most recognizable medieval European dramatic genres, yet much about this term, including the form’s status and influence, remains contested. While the label morality play is a useful one for modern scholars, its origins lie in 18th-century antiquarianism rather than in medieval categorizations. The idea of a distinct morality play genre or tradition is further challenged by the vast array of staging and dramaturgical conventions and techniques displayed by extant playtexts; in the range of different audiences, occasions, and spaces for which they were designed; and in the extent to which they overlap with other dramatic and performance modes (saints’ plays, biblical plays, sotties, debates, mummings, and interludes, for example). Nevertheless, a distinct collection of plays from premodern Europe share characteristics and conceptual and dramaturgic frameworks, justifying their analysis as a group. What links these plays, whether they are written in Latin or in the vernacular, is their sustained use of personification allegory and the clear exposition of a moral sentence. At the core of any morality play sits a central figure, a personification of, say, a universalized concept of “mankind” (Humanum Genus, Everyman, Mankind), an aspect of human nature (Man’s Desire in Menschen Sin en Verganckeljcke Schoonheit), or a specific stage in life (like Youth or the Child). Such figures often also act as a mirror or an avatar for the audience. French moralités often have two central figures who represent opposing moral paths. The plays’ central figures are accompanied by an array of abstract personifications representing virtues, sins, vices, temptations, moral distractions, bad and good advice, and facts of life. These could be faculties or qualities of humankind, such as Flesh, Raison, Wit, or Ignorance; temptations and forces in the external world, such as New Guise, Custom, or Goods; facts of human existence, such as Life, Death, and Kinship; human behaviors, such as Flattery or Deceit; social groups, such as Nobility and Clergy; personifications of God’s qualities, such as Mercy; as well as supernatural beings, such as God and the Devil or Good and Bad Angels. Every part of the performance is enlisted into the allegory, from staging, props, and costumes to the actions of and between performers. Whether the protagonist is saved at the end of the play varies, but often an alignment is explicit between the life journey of the mankind figure and that of Adam, connecting the life of the individual with the great scheme of cosmic history.

Echo of Creation

The article explores the idea of an echo, both literal and structural, that connects Old Norse cosmogony and eschatology. The motif of a bellowing sound or cry appears in cosmogony in the figure of Ymir, “Crier”, who is killed by the Æsir, and from his body the world is created. During the eschatological events the booming sound recurs when Heimdallr blows his horn shortly before the Æsir themselves are killed by their adversaries. A cry is also emitted by Óðinn when he sacrifices himself on the Cosmic Tree. The booming bellow is thus associated with death, especially in the context of implicit or explicit sacrifice. The structural resonance between cosmogony and eschatology is composed of a series of five motifs that reappear in the same sequence at both liminal moments. The eschatology seems to be structurally a repetition of the cosmogony, but with inverted roles: the victims are the gods and the sacrificers are the giants, which is the inverse of the situation during cosmogony. The present analysis sheds light on the sacrificial pattern hidden behind the two events, and helps contextualize the motif of the mighty sound that reappears at both moments in the cosmic history.